100525 + Interview Questions in GENERAL QA IN GENERAL AWARENESS

1.	The correct set of quantum numbers for the unpaired electrons of Flourine atom is
Answer» Electronic configuration of F is 1s² 2s² 2p⁵ now the unpaired electron is in 2p subshell so n = 2 for n = 2 we know L = 1 also possible values for m could be - L to + L and spin quantum number has values like + 1/2 or - 1/2

Discussion

2.	Acidic character of liquid HF increases on addition of which of the following compound ? a. SiF4b. SF6c. BF3d. a and c both
Answer» The acidity of liquid HF can be increased by adding one of several inorganic fluorides that are Lewis acids and accept F– ion (for example, BF3 or SbF5). Correct answer is (d) a and c both Acidity of liquid HF will increased by adding Lewis acid fluorides- ex - BF₃, SiF₄, SbF₅ etc. SiF₄ + 2HF → H₂[SiF₆] \(\rightleftharpoons\) 2H⁺ + [SiFb]^-2 BF₃ + HF → HBF₄ \(\rightleftharpoons\) H⁺ + BF₄

2.

Acidic character of liquid HF increases on addition of which of the following compound ? a. SiF4b. SF6c. BF3d. a and c both

Answer»

The acidity of liquid HF can be increased by adding one of several inorganic fluorides that are Lewis acids and accept F– ion (for example, BF3 or SbF5).

Correct answer is (d) a and c both

Acidity of liquid HF will increased by adding Lewis acid fluorides-

ex - BF₃, SiF₄, SbF₅ etc.

SiF₄ + 2HF → H₂[SiF₆] \(\rightleftharpoons\) 2H⁺ + [SiFb]^-2

BF₃ + HF → HBF₄ \(\rightleftharpoons\) H⁺ + BF₄

Discussion

3.	The correct order of `S_N 2//E2` ratio for the % yield of product of the following halide is- (P)`CH_3-CH-undersetunderset(I)(\|)oversetoverset(Ph)(\|)C-CH_3` , (Q)`CH_3-undersetunderset(Ph)(\|)CH-undersetunderset(I)(\|)CH-CH_3` (R)`CH_3-CH_2-I` , (S)`CH_3-CH-undersetundersetI\|CH-CH_3`A. RgtSgtQgtPB. RgtQgtSgtPC. PgtRgtSgtQD. QgtPgtRgtS
Answer» Correct Answer - A As steric hindrance increases rate of `S_(N_2)` decrease and rate of E2 increases.

Discussion

4.	Observe the esterfication mechanisms for primary and tertiary alcohols. `CH_3-COOH+Ph-undersetunderset(C_2H_5)(\|)oversetoverset(CH_3)(\|)C-OHoverset(Conc.H_2SO_4)to(Y)`A. (X) is optically active while (Y) is optically inactiveB. Both (X) and (Y) are optically activeC. Both (X) and (Y) are optically inactiveD. (X) is optically inactive while (Y) is optically active
Answer» Correct Answer - A X is formed by type-1 mechanism hence configuration is retained. Y is formed by type-2 mechanism hence recemic product is obtained.

Discussion

5.	Observe the esterfication mechanisms for primary and tertiary alcohols. `CH_3-COOH+C_2H_6overset(18)OHoverset(Conc.H_2SO_4)to(P)` `CH_3-COOH+(CH_3)_3C-overset(18)OHoverset(Conc.H_2SO_4)(Q)` In the above reaction (P) and (Q) are respectively :A. `CH_3-oversetoverset(O)(\|\|)C-O-C_2H_6,CH_3-oversetoverset(O)(\|\|)C-overset(18)(O)-undersetunderset(CH_3)(\|)oversetoverset(CH_3)(\|)C-CH_3`B. `CH_3-oversetoverset(O)(\|\|)C-overset(18)(O)-C_2H_5,CH_3-oversetoverset(O)(\|\|)C-O-undersetunderset(CH_3)(\|)oversetoverset(CH_3)(\|)C-CH_3`C. `C_2H_5-oversetoverset(O)(\|\|)C-overset(18)(O)-CH_3, CH_3-oversetoverset(O)(\|\|)C-O-undersetunderset(CH_3)(\|)oversetoverset(CH_3)(\|)C-CH_3`D. `CH_3-oversetoverset(O)(\|\|)overset(18)(O)-C_2H_6,CH_3-oversetoverset(O)(\|\|)C-overset(18)(O)-undersetunderset(CH_3)(\|)oversetoverset(CH_3)(\|)C-CH_3`
Answer» Correct Answer - B P is formed by type-1 mechanism and Q is formed by type-2 mechanism.

Discussion

6.	Assertion : Ethers behave as bases in the presence of mineral Reason : Due to the presence of lone electron pair on the oxygen atom.A. Both A and B are true and R is the correct explanation of A.B. A is true but R is False.C. A is False but R is True.D. Both A and R are false.
Answer» Correct Answer - A Reason is correct explanation for assertion.

Discussion

7.	Assertion : `(CH_3)_(3)COH` when heated with conc. `H_2SO_4` gives isobutylene as the main product and not di-tertiary butyl ether. Reason : All alcohols are radily dehyrated with conc. `H_2SO_4`A. Both A and B are true and R is the correct explanation of A.B. A is true but R is False.C. A is False but R is True.D. Both A and R are false.
Answer» Correct Answer - C `(CH_3)_3overset(+)C` carbocation is quite stable and loses a`H^(+)` ion to form isobutylene as the product.

Discussion

8.	As `S_(N^(2))` reaction at an asymmetric carbon of a compound always gives:A. an enantiomer of the substrateB. a product with opposite optical rotationC. a mixture of diastereomersD. a single stereoisomer
Answer» Correct Answer - D

Discussion

9.	In the button cells widely used in watCHMes and other devices the following reaction takes place : `Zn(s)+Ag_(2)O(s)+H_(2)O(l) rarr Zn^(2+)(aq)+2Ag(s)+2OH^(c-)(aq)` Determine `Delta_(r)G^(c-)` and `E^(c-)` for the reaction.
Answer» Correct Answer - `a. 1.104V` , `b. -2.13xx10^(5)J` `a.` `E_(cell)^(c-)=E_((Ag_(2)O\|Ag)"red")^(c-)-E_((Zn^(2+)\|Zn)"red")^(c-)` `=0.344-(-0.76)=1.104V` `b. Delta_(r)G^(c-)=-nFE^(c-).(n_(cell)=2)` `-2xx96500xx1.104J` `=-2.13xx10^(5)J`

Discussion

10.	Aluminium metal is not extracted directly from Bauxite ore. The ore is first purified to give pure alumina from which aluminium is isolated by electro reduction process. Explain.
Answer» Bauxite `(Al_(2)O_(3).xH_(2)O)` is associated with the impurities of ferric oxide and silica. In case, Bauxite is used directly for the extraction of aluminium, iron and silica present in it would deposit at the cathode during its electrolyte reduction. As a result, aluminium obtained from cathode gets contaminated with iron and silica. This makes the metal brittle. It is readily attacked by air and water.

Discussion

11.	What do you mean by conductivity of a material ? Give its SI units.
Answer» Conductivity is the reciprocal of the resistivity. It can be expressed as— σ = 1/P Its S.I. unit is siemen metre^–1 (Sm^–1) or ohm^–1m^–1

11.

What do you mean by conductivity of a material ? Give its SI units.

Answer»

Conductivity is the reciprocal of the resistivity.

It can be expressed as—

σ = 1/P

Its S.I. unit is siemen metre^–1 (Sm^–1) or ohm^–1m^–1

Discussion

12.	The correct statement regarding the third orbit of hydrgen atom isA. it can accommodate a maximum of nine electronsB. it contains nine degenerated atomic orbitalsC. it contains nine atomic orbitals having three sets of degeneracyD. it contains nine sub-shells.
Answer» Correct Answer - B In H-atom the orbitals (five 3d, three 3p and one 3s) have same energy so they are called degenerate orbitals

Discussion

13.	The specific conductance of a saturated solution of silver bromide is `KScm^(-1)`. The limiting ionic conductivity of `Ag^(+)` and `Br^(-)` ions are x and y respectively. The solubility of silver bromide in g/L is (molar mass of `AgBr=188`)A. `(Kxx1000)/(x-y)`B. `(K)/(x+y)xx188`C. `(Kxx1000xx188)/(x+y)`D. `(x+y)/(k)xx(1000)/(188)`
Answer» Correct Answer - C `AgBr=x+y` `AgBr=(Kxx1000)/(M)` M-molarity of `AgBr` solution 8 (solubility in g/L)`=(Kxx1000)/((x+y))xx188`

Discussion

14.	An alternate substrate for orotate phosphoribosyl transferase is (A) Allopurinol (B) Xanthine (C) Hypoxanthine (D) Adenine
Answer» Correct option (D) Adenine

Discussion

15.	A substrate for enzymes of pyrimidine nucleotide biosynthesis is (A) Allopurinol (B) Tetracylin (C) Chloramphenicol (D) Puromycin
Answer» (A) Allopurinol

Discussion

16.	All of the following statements about puromycin are true except (A) It is an alanyl tRNA analogue (B) It causes premature termination of protein synthesis (C) It inhibits protein synthesis in prokaryotes (D) It inhibits protein synthesis in eukaryotes
Answer» (A) It is an alanyl tRNA analogue

Discussion

17.	All of the following statements about allopurinol are true except (A) It is a structural analogue of uric acid (B) It can prevent uric acid stones in the kidneys (C) It increases the urinary excretion of xanthine and hypoxanthine (D) It is a competitive inhibitor of xanthine oxidase
Answer» (A) It is a structural analogue of uric acid

Discussion

18.	All of the following statements about uric acid are true except (A) It is a catabolite of purines (B) It is excreted by the kidneys (C) It is undissociated at pH above 5.8 (D) It is less soluble than sodium urate
Answer» (C) It is undissociated at pH above 5.8

Discussion

19.	Which pathway is correct for catabolism of purines to form uric acid? (A) Guanylate→Adenylate→Xanthine→hypoxanthine→Uric acid (B) Guanylate→inosinate→Xanthine→hypoxanthine→Uric acid (C) Adenylate→Inosinate→Xanthine hypoxanthine→Uric acid (D) Adenylate→Inosinate→hypoxanthine Xanthine→Uric acid
Answer» (D) Adenylate→Inosinate → hypoxanthine Xanthine→Uric acid

Discussion

20.	what type of resistance can be used for developing strengh
Answer» Follow the below link https://bit.ly/2Hmf8G4

20.

what type of resistance can be used for developing strengh

Answer»

Follow the below link

https://bit.ly/2Hmf8G4

Discussion

21.	In humans end product of purine catabolism is (A) Uric acid (B) Urea (C) Allantoin (D) Xanthine
Answer» (A) Uric acid

Discussion

22.	Arrange `Ce^(3+),La^(3+), Pm^(3)` and `Yb^(3+)` in increasing order of their size -A. `La^(3+) lt Ce^(3+) lt Pm^(3+) lt Yb^(3+)`B. `Yb^(3+) lt Pm^(3+) lt Ce^(3+) lt La^(3+)`C. `La^(3+) = Ce^(3+) lt Pm^(3+) lt Yb^(3+)`D. `Yb^(3+) lt Pm^(3+) lt La^(3+) lt Ce^(3+)`
Answer» Correct Answer - B For tripositive ions of Lanthanoids size decrease regularly as atomic no. increase due to Lanthanoid contraction.

Discussion

23.	निम्नलिखित गद्यांश को ध्यानपूर्वक पढ़कर पूछे गये प्रश्नों के सही विकल्प का चयन कीजिए-महात्मा गाँधी अपना काम अपने हाथ से करने पर बल देते थे। वह प्रत्येक आश्रमवासी से आशा करते थे कि वह अपने शरीर से सम्बन्धित प्रत्येक कार्य, सफाई तक स्वयं करेगा। उनका कहना था कि जो श्रम नहीं करता है, वह पाप करता है और पाप का अन्न खाता है। ऋषि-मुनियों ने कहा है बिना श्रम किये जो भोजन करता है, वह वस्तुतः चोर है। महात्मा गाँधी का समस्त जीवन-दर्शन श्रमसापेक्ष था। उनका समस्त अर्थशास्त्र यही बताता था कि प्रत्येक उपभोक्ता को उत्पादनकर्ता होना चाहिए। उनकी नीतियों की उपेक्षा करने के परिणाम हम आज भी भोग रहे हैं। न गरीबी कम होने में आती है, न बेरोजगारी पर नियंत्रण हो पा रहा है और न अपराधों की वृद्धि हमारे वश की बात रही है। दक्षिण कोरियावासियों ने श्रमदान करके ऐसे श्रेष्ठ भवनों का निर्माण किया है, जिनसे किसी को भी ईष्र्या हो सकती है।(क) महात्मा गाँधी प्रत्येक आश्रमवासी से क्या आशा करते थे?(i) वह आश्रम के सभी काम स्वयं करें(ii) वह परिश्रमशील बने ।(iii) वह अपने शरीर से सम्बन्धित प्रत्येक कार्य स्वयं करें(iv) वह आश्रम के कार्यों में सहयोग करें।(ख) ऋषि-मुनियों ने किस प्रकार के व्यक्ति को चोर कहा है?(i) जो किसी को हानि पहुँचाता है।(ii) जो चोरी करता है।(iii) जो बिना श्रम किये भोजन करता है।(iv) जो असत्य भाषण करता है।(ग) दक्षिण कोरियावासियों ने श्रमदान करके किस प्रकार की चीजों का निर्माण किया है?(i) श्रेष्ठ मन्दिरों का(ii) श्रेष्ठ भवनों का(iii) श्रेष्ठ पुलों का(iv) श्रेष्ठ बाँधों का
Answer» (क) (iii) वह अपने शरीर से सम्बन्धित प्रत्येक कार्य स्वयं करें। (ख) (iii) जो बिना श्रम किये भोजन करता है। (ग) (ii) श्रेष्ठ भवनों का

23.

निम्नलिखित गद्यांश को ध्यानपूर्वक पढ़कर पूछे गये प्रश्नों के सही विकल्प का चयन कीजिए-महात्मा गाँधी अपना काम अपने हाथ से करने पर बल देते थे। वह प्रत्येक आश्रमवासी से आशा करते थे कि वह अपने शरीर से सम्बन्धित प्रत्येक कार्य, सफाई तक स्वयं करेगा। उनका कहना था कि जो श्रम नहीं करता है, वह पाप करता है और पाप का अन्न खाता है। ऋषि-मुनियों ने कहा है बिना श्रम किये जो भोजन करता है, वह वस्तुतः चोर है। महात्मा गाँधी का समस्त जीवन-दर्शन श्रमसापेक्ष था। उनका समस्त अर्थशास्त्र यही बताता था कि प्रत्येक उपभोक्ता को उत्पादनकर्ता होना चाहिए। उनकी नीतियों की उपेक्षा करने के परिणाम हम आज भी भोग रहे हैं। न गरीबी कम होने में आती है, न बेरोजगारी पर नियंत्रण हो पा रहा है और न अपराधों की वृद्धि हमारे वश की बात रही है। दक्षिण कोरियावासियों ने श्रमदान करके ऐसे श्रेष्ठ भवनों का निर्माण किया है, जिनसे किसी को भी ईष्र्या हो सकती है।(क) महात्मा गाँधी प्रत्येक आश्रमवासी से क्या आशा करते थे?(i) वह आश्रम के सभी काम स्वयं करें(ii) वह परिश्रमशील बने ।(iii) वह अपने शरीर से सम्बन्धित प्रत्येक कार्य स्वयं करें(iv) वह आश्रम के कार्यों में सहयोग करें।(ख) ऋषि-मुनियों ने किस प्रकार के व्यक्ति को चोर कहा है?(i) जो किसी को हानि पहुँचाता है।(ii) जो चोरी करता है।(iii) जो बिना श्रम किये भोजन करता है।(iv) जो असत्य भाषण करता है।(ग) दक्षिण कोरियावासियों ने श्रमदान करके किस प्रकार की चीजों का निर्माण किया है?(i) श्रेष्ठ मन्दिरों का(ii) श्रेष्ठ भवनों का(iii) श्रेष्ठ पुलों का(iv) श्रेष्ठ बाँधों का

Answer»

(क) (iii) वह अपने शरीर से सम्बन्धित प्रत्येक कार्य स्वयं करें।

(ख) (iii) जो बिना श्रम किये भोजन करता है।

(ग) (ii) श्रेष्ठ भवनों का

Discussion

24.	The ratio of alcohol and water in to two glasses is 2 : 3 and 5 : 4 respectively. In what ratio should the liquid in both the glasses be mixed to obtain a new mixture containing alcohol and water in the ratio 1 : 1?1. 5 : 92. 9 : 73. 7 : 54. 9 : 11
Answer» Correct Answer - Option 1 : 5 : 9 Given: Ratio of alcohol and water in first glass = 2 : 3 Ratio of alcohol and water in second glass = 5 : 4 Ratio of alcohol and water in the final mixture = 1 : 1 Calculation: Let the ratio of amounts of liquid mixed from first glass and second glass to obtain the final mixture be p : q Amount of alcohol in final mixture = 2/5 × p + 5/9 × q ⇒ 2p/5 + 5q/9 Amount of water in final mixture = 3/5 × p + 4/9 × q ⇒ 3p/5 + 4q/9 Final ratio of alcohol and water in the final mixture = (2p/5 + 5q/9)/(3p/5 + 4q/9) ⇒ (2p/5 + 5q/9)/(3p/5 + 4q/9) = 1/1 ⇒ (2p/5 + 5q/9) = (3p/5 + 4q/9) ⇒ 5q/9 – 4q/9 = 3p/5 – 2p/5 ⇒ q/9 = p/5 ⇒ p/q = 5/9 ∴ The ratio will be 5 : 9

24.

The ratio of alcohol and water in to two glasses is 2 : 3 and 5 : 4 respectively. In what ratio should the liquid in both the glasses be mixed to obtain a new mixture containing alcohol and water in the ratio 1 : 1?1. 5 : 92. 9 : 73. 7 : 54. 9 : 11

Answer» Correct Answer - Option 1 : 5 : 9

Given:

Ratio of alcohol and water in first glass = 2 : 3

Ratio of alcohol and water in second glass = 5 : 4

Ratio of alcohol and water in the final mixture = 1 : 1

Calculation:

Let the ratio of amounts of liquid mixed from first glass and second glass to obtain the final mixture be p : q

Amount of alcohol in final mixture = 2/5 × p + 5/9 × q

⇒ 2p/5 + 5q/9

Amount of water in final mixture = 3/5 × p + 4/9 × q

⇒ 3p/5 + 4q/9

Final ratio of alcohol and water in the final mixture = (2p/5 + 5q/9)/(3p/5 + 4q/9)

⇒ (2p/5 + 5q/9)/(3p/5 + 4q/9) = 1/1

⇒ (2p/5 + 5q/9) = (3p/5 + 4q/9)

⇒ 5q/9 – 4q/9 = 3p/5 – 2p/5

⇒ q/9 = p/5

⇒ p/q = 5/9

∴ The ratio will be 5 : 9

Discussion

25.	Xenon crystallizes in the face-centred cubic lattice and the edge of the unit cell is `620` pm. What is the nearest neighbour distance and what is the redius of xenon atom?A. 219.20pmB. 438.5 pmC. 265.5 pmD. 536.94 pm
Answer» Correct Answer - A `(a)(2)/(sqrt(2))` `=(620)/(2(sqrt(2)))` pm `r=219.20` pm

Discussion

26.	Arrange the following a.`CaH_(2),BeH_(2)`and `TiH_(2)` in order of increasing electrical conductance. b. `LiH,NaH` and `CsH` in order of increasing ionic character. c. `H-H,D-D` and `F-F` in order of increasing bond dissociaton enthalpy. d. `NaH,MgH_(2)` and `H_(2)O` in order of increasing reducing property.
Answer» a. The order of increasing electric conductance is `BeH_(2)ltCH_(2)ltTiH_(2)` Skince `CaH_(2)` is an ionic hydride, it conducts electricity in fused state, `BeH_(2)` being covalent hydride does not conduct electricity at all. `TiH_(2)`, a metallic hydride conducts electricity at room temperature. b. The order of increasing ionic character is `LiHltNaHltCsH` Down the group `(darr)`, from `Li` to `Cs`, electronegativity decreases adn and hence ionic character increases. c. Order of increasing bond dissociation enthalpy: `F-FltH-HltD-D` Due to greater nucleus mass, the bond pair in `D-D` bond is attracted more strongly than in `H-H` bond. Thus, the bond dissociation enthalpy of `D-D` is higher than `H-H` bond. However, due to repulsion between lone pairs of `F` and the bond, `F-F` bond dissociation enthalpy is the minimum, and hence the order. d. Order of increasing reducing property: `H_(2)OltMgH_(2)ltNaH` `NaH` is ionic hydride whereas `H_(2)O` adn `MgH_(2)` are covalent hydrides. Ionic hydrides are stronger reducing agent as compared to covalent hydrides. Hence `NaH` is stronger reducing agent as compared to `H_(2)O` and `MgH_(2)`. Out of `H_(2)O` and `MgH_(2)`, hence `H_(2)O` is weaker reducing agent as compared to `MgH_(2)`.

Discussion

27.	Metallic gold frequently is found in aluminosilicate rocks and it is finely dispersed among other minerals. It may be extracted by treating the crushed rock with aerated sodium cyanide solution. During this process metallic gold is slowly converted t `[Au(CN)_(2)]^(-)`, which is soluble in water. After equlibrium has been reached, the aqueous phase is pumped off and the metallic gold is recovered from it by reacting the gold complex with zinc, which is converted to `[Zn(CN)_(4)]^(2-)`, Gold in nature is frequently alloyed with silver is also oxidised by aerated sodium cyanide solution. Which of the follwing is/are correct for cyanide process of extraction of gold?A. Sodium cynaide is sweet in taste and is also used in making chocolatesB. Sodium cyanide if escapes into ground water then it produces hydrogen cyanide which is toxic to many animals.C. It is an example of pyrometallurgy.D. It is an example of leaching process
Answer» Correct Answer - B::D (B) `HCN` produced with water by `NaCN` and `KCN` is poisonous and have carcinogenic activity.

Discussion

28.	A cubic solid is made of two element `P` and `Q` Atoms of `Q` are the corners of the cube `P` at the body-centre. What is the formula of the compound? What are the coordination number fo `P` and `Q`?
Answer» Number of `Q` atoms per unit cell of cube `= (1)/(8) xx 8 = 1` Number of `P` atoms `= 1//"unit cell`. The formula of the compound is `PQ` or `QP`. The coordinate number of each of `P` and `Q` is 8 becuause the crystal has body-centred cubic structure.

Discussion

29.	Niobium crystallizes in body-centred cubic structure. If the density is `8.55 g cm^(-3)`, calculate the atomic radius of niobium using its atomic mass `93 u`.
Answer» Density, `rho = 8.55 g cm^(-3)` Atomic mass of niobrium, `Aw = 94.0` `rho = (Z_(eff) xx Aw)/(a^(3) xx N_(A))` or `a^(3) = (Z_(eff) xx Aw)/(rho xx N_(A))` Or `a^(3) = (2 xx 94)/(8.55 xx 6.02 xx 10^(23)) = (108)/(51.47) xx 10^(-23)` `= 3.27 xx 10^(-23) cm^(3)` Or `a = (3.27 xx 10^(-23))^(1//3) cm` `= 14.29 cm`

Discussion

30.	\( 1.84 gm \) mixture of \( CaCO _{3} \) & \( MgCO 3 \) exactly produces 0.88 g CO2 on strongly heating, calculate \( \% \) composition of original mixture.
Answer» Let say x.g CaCO₃ is present in mixture. ∴ Weight of MgCO₃ in mixture = (1.84 - x)g. \(\underset{1 mol}{CaCO_3} \overset{\Delta}\longrightarrow \underset{1 mol}{CaO} + \underset{1 mol} {CO_2}\) ∴ Number of moles of CO₂ produced by CaCO₃ = \(\frac x{100}\) mol \(\underset{1 mol}{MgCO_3} \overset{\Delta}\longrightarrow \underset{1 mol}{MgO} + \underset{1 mol}{CO_2}\) ∴ Number of mole of CO₂ produced by MgCO₃= \(\frac{1.84 - x}{84}\) mol But we have given 0.88g CO₂ produced. ∴ \(\left(\frac x{100} + \frac{1.84 - x}{84}\right)\times 44 = 0.88 g\) ∴ \(\frac x{100} + \frac{1.84 - x}{84} = 0.02\) \(84x + 184 - 100 x = 0.02 \times 8400\) \(184 - 16x = 168\) \(16x = 184 - 168\) \(16x = 16\) \(x = 1 g\) ∴ Weight of CaCO₃ in mixture = 1g and Weight of MgCO₃ = (1.84 - 1)g ∴ % composition of CaCO₃ = \(\frac1{1.84} \times 100\) = \(54.35\)% ∴ % composition of MgCO₃ = \(\frac{0.84}{1.84} \times 100\) = \(45.65\)%

30.

\( 1.84 gm \) mixture of \( CaCO _{3} \) & \( MgCO 3 \) exactly produces 0.88 g CO2 on strongly heating, calculate \( \% \) composition of original mixture.

Answer»

Let say x.g CaCO₃ is present in mixture.

∴ Weight of MgCO₃ in mixture = (1.84 - x)g.

\(\underset{1 mol}{CaCO_3} \overset{\Delta}\longrightarrow \underset{1 mol}{CaO} + \underset{1 mol} {CO_2}\)

∴ Number of moles of CO₂ produced by CaCO₃ = \(\frac x{100}\) mol

\(\underset{1 mol}{MgCO_3} \overset{\Delta}\longrightarrow \underset{1 mol}{MgO} + \underset{1 mol}{CO_2}\)

∴ Number of mole of CO₂ produced by MgCO₃= \(\frac{1.84 - x}{84}\) mol

But we have given 0.88g CO₂ produced.

∴ \(\left(\frac x{100} + \frac{1.84 - x}{84}\right)\times 44 = 0.88 g\)

∴ \(\frac x{100} + \frac{1.84 - x}{84} = 0.02\)

\(84x + 184 - 100 x = 0.02 \times 8400\)

\(184 - 16x = 168\)

\(16x = 184 - 168\)

\(16x = 16\)

\(x = 1 g\)

∴ Weight of CaCO₃ in mixture = 1g

and Weight of MgCO₃ = (1.84 - 1)g

∴ % composition of CaCO₃ = \(\frac1{1.84} \times 100\) = \(54.35\)%

∴ % composition of MgCO₃ = \(\frac{0.84}{1.84} \times 100\) = \(45.65\)%

Discussion

31.	The molecular conductivity of acetic acid at infinite dilution is `390 S cm^(2) "mole"^(-1)` and for `0.1` acetic and solution is `5.8 cm^(3) "mole"^(-1)` .The hydrogen ion concentration of the solution isA. `15 xx 10^(-3)`B. `15 xx 10^(-4)`C. `66 xx 10^(-3)`D. `66 xx 10^(-4)`
Answer» Correct Answer - b `alpha = (^^_C)/(^^ ^(prop)) = (5.8)/(390) ~= 15 xx 10^(-3)` `[H^(-)] = Cu = 0.1 xx 15 xx 10^(-3) = 15 xx 10^(-4)`

Discussion

32.	The first clinical gene therapy was done for the treatment of(A) AIDS (B) Cystic fibrosis (C) Cancer (D) SCID
Answer» Correct option is: (D) SCID

Discussion

33.	A 2.05MB 0.50MC 1.78MD 1.02M
Answer» As We know that Density of solution = Mass of solution / Volume of solution therefore , volume of solution = Mass / density = 120+1000 g/ 1.15 g ml^-1 = 1120 100 / 115 = 973.91 ml = 974 10 ^-3 litres Now , n (no. of moles of solute) = 120 g / 60.05 g = 2 mol [since, molecular mass of urea is 60.05 g] Now ,M(Molarity) = n (no. of moles of solute)/ Volume of solution in litres Molarity = 2 / 974 * 10^-3 Molarity = 2000/974 = 2.05 M

33.

A 2.05MB 0.50MC 1.78MD 1.02M

Answer»

As We know that

Density of solution = Mass of solution / Volume of solution

therefore , volume of solution = Mass / density = 120+1000 g/ 1.15 g ml^-1

= 1120 *100 / 115 = 973.91 ml = 974 * 10 ^-3 litres

Now ,

n (no. of moles of solute) = 120 g / 60.05 g = 2 mol [since, molecular mass of urea is 60.05 g]

Now ,M(Molarity) = n (no. of moles of solute)/ Volume of solution in litres

Molarity = 2 / 974 * 10^-3

Molarity = 2000/974 = 2.05 M

Discussion

34.	An azeotropic solution of two liquids will have boiling point lower than two liquids when it.(a) Shows positive deviation from Raoult’s law (b) Shows negative deviation from Raoult’s law (c)Shows no deviation from Raoult’s law(d) None of these
Answer» An azeotropic solution of two liquids will have boiling point lower than two liquids when it Shows positive deviation from Raoult’s law

Discussion

35.	Assertion : Variety of fruit colours in Cucurbita pepo is result of recessive epistasis Reason : In recessive epistatsis, a recessive gene at one locus engances the expression of another gene, at a diferent locus.
Answer» Correct Answer - D Fruit colour of summer squash (Cucurbita pepo) is governed by a gene which produced yellow colour in dominant state (Y) and green colour in recessive state (yy). There is a non-pigment forming epistatic gene which in dominant state (W-) produces white colour (W-Y-,W-yy) while in recessive state it allows the yellow (wwY-) and green (wwyy) expression. This shows dominant epistasis where a dominant epistatic allele suppresses the expression of a non allelic gene whether the latter is dominant or recessive

Discussion

36.	Spices are the buds, fruits, flowers, bark, seeds and roots of plants and trees which are used in their natural / dried form to impart taste to food. Apart from this they also carry a wide range of medicinal properties, aroma and also may impart colour to the food. Which of the following spice has astringent and antifungal properties? a. Cinnamon b. Caraway c. Nigella d. Nutmeg
Answer» a. Cinnamon Cinnamon has astringent and antifungal properties.

36.

Spices are the buds, fruits, flowers, bark, seeds and roots of plants and trees which are used in their natural / dried form to impart taste to food. Apart from this they also carry a wide range of medicinal properties, aroma and also may impart colour to the food. Which of the following spice has astringent and antifungal properties? a. Cinnamon b. Caraway c. Nigella d. Nutmeg

Answer»

a. Cinnamon

Cinnamon has astringent and antifungal properties.

Discussion

37.	difference between multicellular and unicellular
Answer» Unicellular Organisms Multicellular Organisms Unicellular organisms are composed of a single Simple body organization A single cell carries out all necessary life processes The total cell body is exposed to the environment Division of labour is at the organelle level Includes both eukaryotes and prokaryotes A lifespan of a unicellular organism is usually short Multicellular Organisms Multicellular organisms are composed of more than one cell Complex body organization A single cell carries out all necessary life Simple body organization processes Multiple cells perform different functions The total cell body is exposed to the environment Only the outer cells are exposed to the environment Division of labour is at the organelle level Division of labour is at cellular, tissue, organs and organ system level Includes both eukaryotes and prokaryotes Includes only eukaryotes A lifespan of a unicellular organism is usually short Multicellular organisms have a comparatively longer lifespan Injury to the cell leads to the death of the organism Injury to a cell does not cause the death of the multicellular organism

37.

difference between multicellular and unicellular

Answer» Unicellular Organisms Multicellular Organisms

Unicellular organisms are composed of a single

Simple body organization

A single cell carries out all necessary life processes

The total cell body is exposed to the environment

Division of labour is at the organelle level

Includes both eukaryotes and prokaryotes

A lifespan of a unicellular organism is usually short

Multicellular Organisms

Multicellular organisms are composed of more than one cell

Complex body organization

A single cell carries out all necessary life Simple body organization

processes Multiple cells perform different functions

The total cell body is exposed to the environment Only the outer cells are exposed to the environment

Division of labour is at the organelle level Division of labour is at cellular, tissue, organs and organ system level

Includes both eukaryotes and prokaryotes Includes only eukaryotes

A lifespan of a unicellular organism is usually short Multicellular organisms have a comparatively longer lifespan

Injury to the cell leads to the death of the organism Injury to a cell does not cause the death of the multicellular organism

Discussion

38.	“All veins carry deoxygenated blood and all arteries carry oxygenated blood.” 1. Do you agree? 2. Justify your answer.
Answer» 1. Statement is incorrect. 2. Arteries are the blood vessels which carry blood away from the heart. Veins are the blood vessels which carry blood towards the heart. All arteries carry oxygenated blood except pulmonary artery. All veins carry deoxygenated blood except pulmonary vein. Pulmonary artery carry deoxygenated blood towards the lungs and pulmonary vein carry oxygenated blood toward heart.

38.

“All veins carry deoxygenated blood and all arteries carry oxygenated blood.” 1. Do you agree? 2. Justify your answer.

Answer»

1. Statement is incorrect.

2. Arteries are the blood vessels which carry blood away from the heart. Veins are the blood vessels which carry blood towards the heart. All arteries carry oxygenated blood except pulmonary artery.

All veins carry deoxygenated blood except pulmonary vein. Pulmonary artery carry deoxygenated blood towards the lungs and pulmonary vein carry oxygenated blood toward heart.

Discussion

39.	What are lower level of organization in a multicellular organism ? Are these levels also present in unicellular organism
Answer» Lower levels of organization in multicellular organisms are cells, tissues and organs. These are followed by organ system and finally organisms. These levels are absent in unicellular organisms as they have only one cell and therefore no tissue and further levels.

Discussion

40.	Free ammonia is liberated during the catabolism of (A) Cytosine (B) Uracil (C) Thymine (D) All of these
Answer» (D) All of these

Discussion

41.	β -Aminoisobytyrate is formed from catabolism of (A) Cytosine (B) Uracil (C) Thymine (D) Xanthine
Answer» Correct option (C) Thymine

Discussion

42.	Okasaki fragments are small bits of (A) RNA (B) DNA (C) DNA with RNA heads (D) RNA with DNA heads
Answer» (C) DNA with RNA heads

Discussion

43.	DNA does not contain (A) Thymine (B) Adenine (C) Uracil (D) Deoxyribose
Answer» Correct option (C) Uracil

Discussion

44.	The genine of φ×174 bacteriophage is interesting in that if contains (A) No DNA (B) DNA with uracil (C) Single stranded DNA (D) Triple standard DNA
Answer» (C) Single stranded DNA

Discussion

45.	If a smart material generates voltage due to temperature difference, it is a. Pyroelectric b. photovoltaic c. piezoelectric d. liquid crystal
Answer» a. Pyroelectric

Discussion

46.	If a smart material generates electricity due to deformation, it is a. Photochromic b. photovoltaic c. piezoelectric d. liquid crystal
Answer» c. piezoelectric

Discussion

47.	Intermetallic compounds a. Easily deform b. easily cross-slip c. easily slip across grain boundaries d.have high Peierls stress
Answer» d.have high Peierls stress

Discussion

48.	Hydrostatic pressure in renal glomerular capillaries A. Is lower than pressure in efferent arterioles.B. Rises when afferent arterioles constrict. C. Is higher than in most capillaries at heart level. D. Falls by 10 per cent when arterial pressure falls by 10 per cent. E. Falls along the length of the capillary.
Answer» A. False It must be higher to maintain blood flow. B. False The pressure drop across the afferent arterioles increases as they constrict. C. True The afferent arterioles offer relatively little resistance. D. False Redistribution of renal vascular resistance due to autoregulation tends to maintain glomerular hydrostatic pressure and hence filtration. E. True Hydrostatic pressure falls due to vascular resistance; oncotic pressure rises due to loss of protein-poor filtrate; both these factors reduce filtration pressure along the length of the glomerular capillary.

48.

Hydrostatic pressure in renal glomerular capillaries A. Is lower than pressure in efferent arterioles.B. Rises when afferent arterioles constrict. C. Is higher than in most capillaries at heart level. D. Falls by 10 per cent when arterial pressure falls by 10 per cent. E. Falls along the length of the capillary.

Answer»

A. False It must be higher to maintain blood flow.

B. False The pressure drop across the afferent arterioles increases as they constrict.

C. True The afferent arterioles offer relatively little resistance.

D. False Redistribution of renal vascular resistance due to autoregulation tends to maintain glomerular hydrostatic pressure and hence filtration.

E. True Hydrostatic pressure falls due to vascular resistance; oncotic pressure rises due to loss of protein-poor filtrate; both these factors reduce filtration pressure along the length of the glomerular capillary.

Discussion

49.	Secretion of renin A. Occurs in the stomach during infancy. B. Is stimulated by the hormone angiotensin I. C. Leads to raised levels of angiotensin II in the blood. D. Is stimulated by a fall in extracellular fluid volume. E. Inhibits ACTH secretion by the pituitary gland.
Answer» A. False Rennin is the enzyme secreted by infant’s gastric mucosa which curdles milk. B. False Renin promotes angiotensin I formation from a circulating precursor. C. True Angiotensin I is converted to angiotensin II by a converting enzyme in the lungs. D. True Renin’s action helps to restore this volume. E. False There is no direct feedback between the two systems.

49.

Secretion of renin A. Occurs in the stomach during infancy. B. Is stimulated by the hormone angiotensin I. C. Leads to raised levels of angiotensin II in the blood. D. Is stimulated by a fall in extracellular fluid volume. E. Inhibits ACTH secretion by the pituitary gland.

Answer»

A. False Rennin is the enzyme secreted by infant’s gastric mucosa which curdles milk.

B. False Renin promotes angiotensin I formation from a circulating precursor.

C. True Angiotensin I is converted to angiotensin II by a converting enzyme in the lungs.

D. True Renin’s action helps to restore this volume.

E. False There is no direct feedback between the two systems.

Discussion

50.	7 years ago a father was 7 times as old as his son, 3 years hence he will be only 3 times to the age of his son. Their present ages are:1. 45, 122. 42, 123. 36, 74. 48, 15
Answer» Correct Answer - Option 2 : 42, 12 Given: 7 years ago father was 7 times as old as his son 3 years from now father will be 3 times to the age of his son Calculation: Let the present age of the son be x Age of the father 7 years ago = 7 × (x - 7) Age of the father 3 years from now = 3 × (x + 3) Also, Age of the father 3 years from now = 7 × (x - 7) + 10 7 × (x - 7) + 10 = 3 × (x - 3) ⇒ 7x - 49 + 10 = 3x - 9 ⇒ 4x = 48 ⇒ x = 12 Present age of the father = 3 × (x + 3) - 3 ⇒ 3 × 15 - 3 ⇒ 42 ∴ Present age of father and son is 42 and 12 years respectively.

50.

7 years ago a father was 7 times as old as his son, 3 years hence he will be only 3 times to the age of his son. Their present ages are:1. 45, 122. 42, 123. 36, 74. 48, 15

Answer» Correct Answer - Option 2 : 42, 12

Given:

7 years ago father was 7 times as old as his son

3 years from now father will be 3 times to the age of his son

Calculation:

Let the present age of the son be x

Age of the father 7 years ago = 7 × (x - 7)

Age of the father 3 years from now = 3 × (x + 3)

Also, Age of the father 3 years from now = 7 × (x - 7) + 10

7 × (x - 7) + 10 = 3 × (x - 3)

⇒ 7x - 49 + 10 = 3x - 9

⇒ 4x = 48

⇒ x = 12

Present age of the father = 3 × (x + 3) - 3

⇒ 3 × 15 - 3

⇒ 42

∴ Present age of father and son is 42 and 12 years respectively.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

The correct set of quantum numbers for the unpaired electrons of Flourine atom is

Acidic character of liquid HF increases on addition of which of the following compound ? a. SiF4b. SF6c. BF3d. a and c both

Assertion : Ethers behave as bases in the presence of mineral Reason : Due to the presence of lone electron pair on the oxygen atom.A. Both A and B are true and R is the correct explanation of A.B. A is true but R is False.C. A is False but R is True.D. Both A and R are false.

As `S_(N^(2))` reaction at an asymmetric carbon of a compound always gives:A. an enantiomer of the substrateB. a product with opposite optical rotationC. a mixture of diastereomersD. a single stereoisomer

In the button cells widely used in watCHMes and other devices the following reaction takes place : `Zn(s)+Ag_(2)O(s)+H_(2)O(l) rarr Zn^(2+)(aq)+2Ag(s)+2OH^(c-)(aq)` Determine `Delta_(r)G^(c-)` and `E^(c-)` for the reaction.

Aluminium metal is not extracted directly from Bauxite ore. The ore is first purified to give pure alumina from which aluminium is isolated by electro reduction process. Explain.

What do you mean by conductivity of a material ? Give its SI units.

The correct statement regarding the third orbit of hydrgen atom isA. it can accommodate a maximum of nine electronsB. it contains nine degenerated atomic orbitalsC. it contains nine atomic orbitals having three sets of degeneracyD. it contains nine sub-shells.

An alternate substrate for orotate phosphoribosyl transferase is (A) Allopurinol (B) Xanthine (C) Hypoxanthine (D) Adenine

A substrate for enzymes of pyrimidine nucleotide biosynthesis is (A) Allopurinol (B) Tetracylin (C) Chloramphenicol (D) Puromycin

All of the following statements about puromycin are true except (A) It is an alanyl tRNA analogue (B) It causes premature termination of protein synthesis (C) It inhibits protein synthesis in prokaryotes (D) It inhibits protein synthesis in eukaryotes

All of the following statements about allopurinol are true except (A) It is a structural analogue of uric acid (B) It can prevent uric acid stones in the kidneys (C) It increases the urinary excretion of xanthine and hypoxanthine (D) It is a competitive inhibitor of xanthine oxidase

All of the following statements about uric acid are true except (A) It is a catabolite of purines (B) It is excreted by the kidneys (C) It is undissociated at pH above 5.8 (D) It is less soluble than sodium urate

what type of resistance can be used for developing strengh

In humans end product of purine catabolism is (A) Uric acid (B) Urea (C) Allantoin (D) Xanthine

Arrange `Ce^(3+),La^(3+), Pm^(3)` and `Yb^(3+)` in increasing order of their size -A. `La^(3+) lt Ce^(3+) lt Pm^(3+) lt Yb^(3+)`B. `Yb^(3+) lt Pm^(3+) lt Ce^(3+) lt La^(3+)`C. `La^(3+) = Ce^(3+) lt Pm^(3+) lt Yb^(3+)`D. `Yb^(3+) lt Pm^(3+) lt La^(3+) lt Ce^(3+)`

The ratio of alcohol and water in to two glasses is 2 : 3 and 5 : 4 respectively. In what ratio should the liquid in both the glasses be mixed to obtain a new mixture containing alcohol and water in the ratio 1 : 1?1. 5 : 92. 9 : 73. 7 : 54. 9 : 11

Xenon crystallizes in the face-centred cubic lattice and the edge of the unit cell is `620` pm. What is the nearest neighbour distance and what is the redius of xenon atom?A. 219.20pmB. 438.5 pmC. 265.5 pmD. 536.94 pm

A cubic solid is made of two element `P` and `Q` Atoms of `Q` are the corners of the cube `P` at the body-centre. What is the formula of the compound? What are the coordination number fo `P` and `Q`?

Niobium crystallizes in body-centred cubic structure. If the density is `8.55 g cm^(-3)`, calculate the atomic radius of niobium using its atomic mass `93 u`.

\( 1.84 gm \) mixture of \( CaCO _{3} \) &amp; \( MgCO 3 \) exactly produces 0.88 g CO2 on strongly heating, calculate \( \% \) composition of original mixture.

The molecular conductivity of acetic acid at infinite dilution is `390 S cm^(2) "mole"^(-1)` and for `0.1` acetic and solution is `5.8 cm^(3) "mole"^(-1)` .The hydrogen ion concentration of the solution isA. `15 xx 10^(-3)`B. `15 xx 10^(-4)`C. `66 xx 10^(-3)`D. `66 xx 10^(-4)`

The first clinical gene therapy was done for the treatment of(A) AIDS (B) Cystic fibrosis (C) Cancer (D) SCID

A 2.05MB 0.50MC 1.78MD 1.02M

An azeotropic solution of two liquids will have boiling point lower than two liquids when it.(a) Shows positive deviation from Raoult’s law (b) Shows negative deviation from Raoult’s law (c)Shows no deviation from Raoult’s law(d) None of these

Assertion : Variety of fruit colours in Cucurbita pepo is result of recessive epistasis Reason : In recessive epistatsis, a recessive gene at one locus engances the expression of another gene, at a diferent locus.

difference between multicellular and unicellular

“All veins carry deoxygenated blood and all arteries carry oxygenated blood.” 1. Do you agree? 2. Justify your answer.

What are lower level of organization in a multicellular organism ? Are these levels also present in unicellular organism

Free ammonia is liberated during the catabolism of (A) Cytosine (B) Uracil (C) Thymine (D) All of these

β -Aminoisobytyrate is formed from catabolism of (A) Cytosine (B) Uracil (C) Thymine (D) Xanthine

Okasaki fragments are small bits of (A) RNA (B) DNA (C) DNA with RNA heads (D) RNA with DNA heads

DNA does not contain (A) Thymine (B) Adenine (C) Uracil (D) Deoxyribose

The genine of φ×174 bacteriophage is interesting in that if contains (A) No DNA (B) DNA with uracil (C) Single stranded DNA (D) Triple standard DNA

If a smart material generates voltage due to temperature difference, it is a. Pyroelectric b. photovoltaic c. piezoelectric d. liquid crystal

If a smart material generates electricity due to deformation, it is a. Photochromic b. photovoltaic c. piezoelectric d. liquid crystal

Intermetallic compounds a. Easily deform b. easily cross-slip c. easily slip across grain boundaries d.have high Peierls stress

Secretion of renin A. Occurs in the stomach during infancy. B. Is stimulated by the hormone angiotensin I. C. Leads to raised levels of angiotensin II in the blood. D. Is stimulated by a fall in extracellular fluid volume. E. Inhibits ACTH secretion by the pituitary gland.

7 years ago a father was 7 times as old as his son, 3 years hence he will be only 3 times to the age of his son. Their present ages are:1. 45, 122. 42, 123. 36, 74. 48, 15

\( 1.84 gm \) mixture of \( CaCO _{3} \) & \( MgCO 3 \) exactly produces 0.88 g CO2 on strongly heating, calculate \( \% \) composition of original mixture.