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This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The volumeof perhydrol which on decompostion gives 1L of O_(@) at STP is |
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Answer» 10mL |
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| 2. |
Which of the following is not the correct order of stability of the given pairs |
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Answer» `underset((I)""(II))(overset(Ө)(C)H_(2)-overset(overset(O)(||))(C)-H harr CH_(2)=overset(overset(O^(-))(|))(C)-H" "II gt I)`<BR>`underset((I)""(II))(Br-CH-overset(Ө)(N)H_(2) harr overset(Ө)(Br)=CH-NH_(2)" "I gt II)` |
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| 5. |
Which of following could act as propelleant for rockets? |
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Answer» LIQUID oxygen+liquid argon |
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| 6. |
Total number of products on monochlorination of n-pentane in presence of sunlight are: |
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Answer» (1) `underset(Cl)underset(|)CH_(2)-CH_(2)-CH_(2)-CH_(2)-CH_(3)` (2) `CH_(3)-underset(Cl)underset(|)CH-CH_(2)-CH_(2)-CH_(3)(+-)+` (3) `CH_(3)-CH_(2)-underset(Cl)underset(|)CH-CH_(2)-CH_(3)` Total number of PRODUCTS = 1+2+1=4 |
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| 8. |
What is slaking of lime ? |
| Answer» Solution :The ADDITION of limited AMOUNT of water BREAKS the lump of LIME. This process is called slaking of lime. | |
| 9. |
Which of the following alcohol will give a black precipitate of manganese dioxide with alkaline KMnO_(4) ? |
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Answer» `CH_(3)CH_(2)OH` |
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| 10. |
Which is the actual order of N, O, F and Cl as per oxidizing agent ? |
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Answer» `FgtOgtClgtN` |
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| 11. |
What is the total number of radial and angular nodes present in 5f orbital? |
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Answer» number of ANGULAR nodes = l TOTAL = 1 + 3 = 4 (or) Total number of nodes = n-1 |
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| 12. |
Which of the following contain more number of molecules |
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Answer» 1 gm `H_(2)` moles = `(1)/(2),(1)/(44),(1)/(80),(1)/(28)` `therefore` highest in 1gm `H_(2)` |
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| 13. |
Which gas is produce when washing soda is reacted with acid ? |
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Answer» `H_(2)` |
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| 14. |
which point defect in crystals of a solid does not change the density of the soild ? |
| Answer» SOLUTION :FRENKEL DEFECT | |
| 15. |
The weight of AgCl precipitated when a solution containing 5.85 g of NaCl is added to a solution containing 3.4g of AgNO_3 is |
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Answer» 28g No. of moles of `AgNO_3=(3.4)/(170)=0.02` No. of moles of NaCl `=(5.85)/(58.5)=0.1` limiting REAGENT = `AgNO_3` 1 mole of `AgNO_3` produces 1 mole of AgCl 0.02 mole of `AgCO_3` produce 0.02 mole of AgCl Weight of AgCl produced = `0.02xx143.5=2.870 G` |
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| 17. |
When lithium is heated in air mainly forms the monoxide and not peroxide. Why? |
| Answer» SOLUTION :It is because `Li^(+)` ion is smaller in SIZE. It is stabilised more by smaller anion, oxide ion `(O^(2-))` as compared to PEROXIDE ion `(O_(2)^(2))`. | |
| 18. |
Which of the following has minimum value of flocculating power:- |
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Answer» `Pb^(+2)` |
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| 19. |
Which of the following species have peroxide ion peroxy linkage ? |
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Answer» `H_(2)O_2` 
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| 20. |
underset((ii)H^(+))overset(("i")HCN)to Product , Product obtained in the reaction is : D-(+) - Glyceraldelyde |
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Answer» Diastereomer 
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| 21. |
What is the bond length in O_(3) molecule ? |
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Answer» EQUAL to O = O |
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| 23. |
Wurtz reaction is used to unit |
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Answer» TWO alkyl HALIDES |
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| 24. |
When -0.532 g of benzene ( C_(6)H_(6)) , boilingpoint 353 K, is burnt with excess of oxygen in a constant volume system, 22.3kJ of heat is given out. Calculate DeltaH for the combustion process ( R = 8.13 J K^(-1) mol^(-1)) |
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Answer» Calculate `DeltaH` as in Solved Problem above. |
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| 25. |
Write the chemical equations for the reactions involved in solvay process of preparation of sodium carbonate |
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Answer» Solution :Solvay PROCESS: The Solvay process is represented by the below chemical equations: (i) `2NH_(3) + H_(2)O + CO_(2) tounderset(Ammonium carbonate) ((NH_(4))_(2)CO_(3)` `(NH_(4))_(2) CO_(3) + H_(2)O + CO_(2)tounderset(Ammonium bicarbonate)(2NH_(4)HCO_(3))` `NH_(4)HCO_(3)+NaCItounderset(Ammonium bicarbonate)(NH_(4)CI+NaHCO_(3))` `2NaCItounderset(SODIUMCARBONATE)(Na__(2)CO_(3))+CO_(2)+H_(2)O` |
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| 26. |
Which of the following transitions involves maximum amount of energy? |
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Answer» `M_((G))^(-) to M_((g)) ` |
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| 27. |
Which of the following does not contain coordinate covalent bond? |
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Answer» `NH_(4)^(+)` |
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| 28. |
Which of the following statement is not true for a lyophobic sol |
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Answer» it can be EASILY solvated |
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| 29. |
Name the species that will be isoelectronic with Mg^(2+) |
| Answer» SOLUTION :`MG^(2+)` (10 electrons),REFER ANSWER of (i) | |
| 30. |
Which of the following is not a white crystalline solid ? |
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Answer» `LiHCO_(3)` |
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| 31. |
Which of the following will react with acetone to give a product containing |
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Answer» `C_(6)H_(5)NH_(2)` 
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| 32. |
What is the energy (in eV) required to excite the electron from n=1 to n=2 state in hydrogen atom ? (n=principal quantum number ) |
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Answer» 13.6 `E_2-E_1=13.6(1/n_2^2-1/n_1^2)` or , `DeltaE=13.6(1/n_1^2-1/n_2^2) =13.6(1-1/4) =10.2 EV` |
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| 33. |
Two volatile liquids A and B differ in their boiling point by 15^(@)C. The process which can be used to separate them is |
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Answer» Fractional DISTILLATION |
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| 34. |
What can be permitted concentration of Ag^(+) ionsin0.1 M HCN solution buffered at pH =3 without causing precipitation of AgCN. K_(sp) " of " AgCN =1.2 xx 10 ^(-16),K_a " of "HCN = 4.8 xx 10^(-10 ) |
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Answer» `1.6 xx 10 ^(-5)M` ` rArr (10 ^(-3) xx [CN^(-) ])/( (0.1) )=4.8 xx 10 ^(-10) ` `rArr [CN^(-) ] =4.8 xx 10 ^(-8) ` ` rArr [Ag^(+)] =(1.2 xx 10 ^(-16))/( 4.8 xx 10 ^(-8) ) = 2.5 xx 10 ^(-9) ` |
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| 35. |
The solubility of salt of weak acid MX (e.g. phosphoric) is increase at tower pH explain with equation. |
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Answer» Solution :The solubility of salt of weak acid like `Na_3PO_4` increases at lower pH because as lower pH concentration of anion `X^-` decreases due to protonation so `X^-` decrease and solubility of MX increases. `MX HARR M_((aq))^(+) + X_((aq))^(-)`…(Eq. -i) `K_(sp)=[M^+][X^-]`...(Eq.-ii) MX is the salt of weak acid (HX) ionization of weak acid is as follows . `HX_((aq)) hArr H_((aq))^(+) + X_((aq))^(-)` ...(Eq.-iii) (Eq.-iii) ionization constant for weak acid `K_a=([H_((aq))^+][X_(aq)^-])/(HX_((aq))]`...(Eq.-iv) `THEREFORE K_a/([H^+])=([X^-])/([HX])` `([H^+])/K_a +1 = ([HX])/([X^-])+1` `because ([H^+]+K_a)/K_a=([HX]+[X^-])/([X^-])` `K_a/([H^+]+K_a)=([X^-])/([HX]+[X^-])=F` ....(Eq.-v) So `[H^+]` increase pH decreases and with of .f. decrease. SUPPOSE , for given salt MX at given pH .S. is molar . `K_(sp)=[M^+][X^-]=S-(f S) =S^2(f)` `therefore S=sqrt(K_(sp)/f)` ...(Eq.-vi) As per (Eq.-v) `1/f=(([H^+]+K_a)/K_a)`....(Eq.-vii) `S=((K_(sp){(H^+)+(K_a)})/K_a)^(1/2)` ....(Eq.-viii) As per this EQUATION `S prop [H^+] pH prop 1/([H^+])` |
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| 36. |
Write the electronic configuration of O_(2) molecule in the singlet state. |
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Answer» Solution : Ordinary ` O_(2)`moleucle has the electronic configuration `sigma_(1s)^(2) sigma_(1s)^(**2) sigma_(2s)^(2) sigma_(2p_(z))^(**2).pi_(2P_(x))^(2)pi_(2P_(y))^(2)pi_(2P_(x))^(**1)pi_(2P_(y))^(**2)` Multiplicity= (2S + 1 ) Where S =total electron spin ` = 2 ((1)/(2) + (1)/(2)) + 1 = 3 ` ""` [ S = (1)/(2) + (1)/(2) ` because two electons have parallel spins] Hence , it is in the triplet STATE if two ELECTRONS pair up ` S = (1)/(2) - (1)/(2) = 0 ` (because they will have opposite spin) Spin multiplicity = `2S + 1 = 0 + 1 = 1 ` This is called singlet state . Hence, electronic configuration of `O_(2)` moleculein the single state will be `sigma_(1s)^(2) sigma_(1s)^(**2) sigma_(2s)^(2) sigma_(2s)^(**2)sigma_(2p_(z))^(2).pi_(2P_(x))^(2)pi_(2P_(y))^(2)pi_(2P_(x))^(**2)pi_(2P_(y))^(**0)` |
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| 37. |
The type of hybrid orbitals of nitrogen in NO_(2)^(+), NO_(3)^(-)and NH_(4)^(+)respectively are expected to be |
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Answer» `SP, sp^(3) and sp^(2)` |
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| 38. |
What is oxidising agent ? |
| Answer» Solution :During reaction, which SUBSTANCE donate oxygen or accept HYDROGEN such substance is known as OXIDISING agent. | |
| 39. |
Which of the following will not yield tartaric acid |
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Answer» HYDROLYSIS of glyoxal cyanohydrin |
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| 40. |
Which of the following pair cannot exist together in solution ? |
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Answer» `NaHCO_(3)+NaOH` |
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| 41. |
which of the following is not true about structure of diamond and graphite? |
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Answer» In DIAMOND, each carbon is `sp^(3)` hybridised while in GRAPHITE each carbon is `sp^(2)` hybridesed. |
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| 42. |
When super cooled freezes, its temperature suddenly rises, the Delta H for the spontaneous process is equal to |
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Answer» ethalpy of fussion |
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| 43. |
What time will be required for a sample of ethane (C_2 H_6) to effuse through an orifice if a similar sample of butane (C_4 H_(10)) required 2 minutes 23 seconds ? |
| Answer» SOLUTION :1 MIN, 43 SEC. | |
| 44. |
Which one of the following is responsible for depletion of the ozone layer in the upper strata of the atmosphere ? |
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Answer» polyhalogens |
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| 45. |
Which is not paramagnetic of the following? |
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Answer» `N_(2)^(+)` `(sigma_(1S))^(2)(sigma_(1s)^(**))^(2)(sigma_(2s))^(2)(sigma_(2p_(z)))^(2)(sigma_(2s)^(**))^(2)(pi_(2p_(x)))^(2)(pi_(2p_(y)))^(2)` |
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| 46. |
What are the significance of Psi and Psi^2 ? |
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Answer» Solution :In an atom the WAVE FUNCTION `PSI` for an ELECTRON has no physical significance as such. However, its square i.e., `Psi^2` at any point GIVES the intensity of the electron wave at that point. In view of Heisenberg.s uncertainty principle, it shows the probability of finding the electron at that point and therefore, termed as probability density. |
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| 47. |
Which carbocation is most stable |
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Answer»
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| 48. |
The treatment of CH_(3)MgX with CH_(3)C-=C-H produces |
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Answer» `CH_(4)` `CH_(3)MgX+CH_(3)C-=C-H rarr CH_(4)+CH_(3)C-=CMgX` |
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| 49. |
Which of the following changes cannot increase the volume of a gas by 4 times |
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Answer» T is DOUBLED, P is DECREASED to half |
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