InterviewSolution
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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 5801. |
From your answers write the need of learning IUPAC name and structural formula of compounds. |
| Answer» Solution : From the molecular formula alone, we cannot KNOW the NATURE of the compound. Because, `C_4H_10`may also REPRESENT a butane molecule or a molecule of 2-methylpropane. Therefore, we MUST know the structural formula and IUPAC name of the compound. | |
| 5802. |
From top to bottom in a group of the periodic table the electropositive character of the element |
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Answer» increases |
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| 5803. |
From the values of electronegativities how can conclude about the nature of bond formed? |
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Answer» Solution :(i) If the electronegativity is less than 1.7, then bond will be COVALENT. (II) If the electronegativity is more than 1.7, then the bond will be IONIC. Example : (i) `N_(2):N =3.0`, difference = 0 (Covalent bond) (ii) `MgF_(2), Mg=1.2, F=4`, difference = 2.8 (Ionic bond) The electronegativities of some elements are as given below: 
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| 5804. |
Fromthe tablegivenbelow, furnishyourpointsof inference |
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Answer» Solution :(i) At `25^@ C`, 36g NaCl is dissolved in 100g water to give a saturated solution. (ii) At `25^@ C,` 95g NABR is dissolved in 100g water to get a saturated solution. (iii) At `25^@ C`, 184g Nal is dissolved in 100g water to get a saturated solution. (iv) SOLUBILITY of a solute at a given solvent at a particular TEMPERATURE is defined as the number of grams of solute necessary to saturate 100g of the solvent at that temperature. In the above tabular column, we infer that solubility of Nal is the highest and the solubility ofNaCl is the lowest. (v) All the NaCl, NaBr, Nal solution in water are called aqueous solutions. (VI) Depending upon the amount of the solute, the solutions are classified as saturated and unsaturated solution. (vii) The above solutions are saturated solutions. |
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| 5805. |
From the part of a periodic table, answer the following questions (a) Atomic number of oxygen is 8. What would be the atomic number of, Fluorine ? (b) Out of 'X' and 'Q' which element has larger atomic size ? Give reason for your answer. (c) Out of 'Y' and 'Z' which element has smaller atomic size ? Give reason for your answer. |
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Answer» Solution :(a) Atomic number of Fluorine is (8 + 1) = 9. (b) SINCE the atomic size of the elements DECREASES along a period the element 'X' has a smaller size than element 'Q'. (c) Since the atomic size of the elements increases down the group, element 'Y' has a smaller size than element 'Z'. |
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| 5806. |
From the part of the periodic table given, answer the following questions. (a) Which is the most reactive metal ?(b) Name the family of L, Q, R, T. (c) Name one element of group 2 and 15,(d) Name one member of group 18 other than neon. (e) Give the name of the element S placed below carbon in group 14. |
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Answer» Solution :(a) The element Z is the most reactive METAL. (B) The elements are PRESENT in group 17. The family is that of halogens. (c) One element belonging to group 2 is ~0cium (Ca) while one present in to group 15 is nitrogen (N). (d) The element ARGON (Ar) is also present m group 18. (e) The element is silicon (Si). |
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| 5807. |
From the organic compounds given below, choose one compound incase which relates to the description[Ethyne, ethanol, acetic acid, ethene] An organic compound whose functional group is carboxyl. |
| Answer» SOLUTION :ACETIC ACID | |
| 5808. |
From the list of the organic compounds ethanol, ethane, methanol, methane, ethyne and ethane, name a compoundWhich forms methanol on oxidation in the presence of copper at 200^@C. |
| Answer» SOLUTION :METHANE | |
| 5809. |
From the list of the organic compounds ethanol, ethane, methanol, methane, ethyne and ethane, name a compoundWhich forms chloroform on halogenation in the presence of sunlight |
| Answer» SOLUTION :METHANE | |
| 5810. |
From the list given below, select the word(s) required to correctly complete blanks (i) to (v) in the following passage: [ammonia, ammonium, carbonate, carbon dioxide, hydrogen, hydronium, hydroxide, precipitate, salt, water.] A solution X turns blue litmus red, so it must contain (i) _____ ions, another solution Y turns red litmus blue and therefore, must contain (ii) ______ ions. When solutions X and Y are mixed together, the products will be a (iii) _____ and (iv) ____. If a piece of magnesium were put into solution X, (v) _____ gas would be evolved. |
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Answer» Solution :(i) HYDRONIUM (II) HYDROXIDE (iii) salt (IV) water (v) hydrogen |
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| 5811. |
From thegraph given below compare theintermolecular forces of attraction in A and B. |
| Answer» Solution :At extermely LOW pressure, all the gases behave almost ideally. From the GRAPH, it is known thatas pressure increases, PV decreases showing thatwith increasein pressure theintermolecular spaces between molecules of B can be decreased to a great extent. This is possible when theintermolecular FORCES between themolecules are more. At a certian stage PV reaches minimum and then increases showing that further increase inpressure cannotdecreae thevolume to that extent. While in A though the INTERMOLECULAR spaces are more, thedecrease in volume of'A ' with theincrease ofpressure is lesser than ideal gas. This shows that intermolecular forces of attraction of A are LESS. | |
| 5812. |
From the formulae listed in the box, choose one in each case corresponding to the salt having the given description: AgCl,CuCO_(3),CuSO_(4)*5H_(2)O,KNO_(3),NaCl,NaHSO_(4),Pb(NO_(3))_(2) , (i) an acid salt (ii) an insoluble chloride (iii) on treating with concentrated sulphuric acid, this salt changes from blue to white. (iv) on heating, this salt changes from green to black. (v) this salt gives nitrogen dioxide on heating. |
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Answer» Solution :(i) `NaHSO_(4)` (ii) AGCL (iii) `CuSO_(4)*5H_(2)O` (iv) `CuCO_(3)` (v) `Pb(NO_(3))_(2)` |
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| 5813. |
From the following part of the periodic table, answer the following questions: (i) Which is the most reactive metal ? (ii) Name the family of fluorine Q, R, T. (iii) Name one element each of group 2 and 15. (iv) Give the name of the element P placed below carbon. (v) Compare X and P with respect to the size of atoms. |
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Answer» <P> Solution :(i) Z.(ii) Halogens. (iii) Magnesium and nitrogen. (iv) SILICON. (v) X has bigger SIZE than P because X has less effective NUCLEAR charge. |
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| 5814. |
From the following elements : _(4)Be,_(9)F,_(19)K,_(20)Ca (i) Select the element having one electron in the outermost shell. (ii) Two elements of the same group. Write the formula and mention the nature of the compound formed by the union of _(19)K and element X (2,8,7). |
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Answer» Solution :(i) The elements which have one ELECTRON in the outermost shell are `_(19)K=2,8,8,1` (II) Two elements of the same GROUP are Beryllium (Be) and Calcium (CA). `_(4)Be=2,2` `_(20)Ca=2,8,8,2` Formula of element K and element X: Both elements K and X have valency one. So,  It is an electrovalent COMPOUND. |
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| 5815. |
From the following elements : ""_(4) Be,""_(9) K, ""_(20) Ca (i) select the element having one electron in the outermost shell. (ii) two elements of the same group. Write the formula of and mention the nature of the compound formed by the union of ""_(19) K and element X(2, 8, 7). |
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Answer» Solution :(i) `""_(19) K` has one electron in the outermost shell. It has the electronic configuration : `2,8,8,1` `""_(4) Be and ""_(20) Ca` belong to Group 2. Both of them have two electrons in the outermost shell and therefore belong to Group 2 (same group). Formula of the compound formed by the UNION of `""_(19) K and X(2, 8, 7)` is : `KX`. Nature of the compound will be IONIC because K (2, 8, 8, 1) will donate one electron to X. This will complete the octet of both. |
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| 5816. |
From the following elements: ""_4Be, ""_9F, ""_19K, ""_20Ca(i)Select the element having one electron in the outermost shell.(ii) Two elements of the same group. Write the formula and mention the nature the compound formed by the union of 19K and element X (2,8, 7). |
Answer» SOLUTION : IONIC or ELECTROVALENT BOND is FORMED. |
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| 5817. |
From the following elements : ""_(20)Ca,""_(3)Li,""_(11)Na,""_(10)Ne (a) Select the element which has two shells, both of which are completely filled with electrons. (b) Select two elements of the same group. |
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Answer» Solution :Element in which two shells are completely filled with electrons is `""_(10)NE` (2, 8). Two ELEMENTS of the same GROUP are `""_(3)LI` (2,1) and `""_(11)Na` (2,8, 1). |
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| 5818. |
From the following , choose the ionic compounds : (i)CaCl_(2) (ii) C Cl_(4)(iii) KCl (iv) H_(2)S |
| Answer» SOLUTION :(i) `CaCl_(2) and` (II) KCI | |
| 5819. |
From the following , choose the most reactive and the least reative metals " Ca , Na Cu ,Ag and Au. |
| Answer» SOLUTION :Most REACTIVE metal : NA , LEAST reactive metal : AU | |
| 5820. |
From the following choose the basic oxides and acidic oxides :CaO, SO_(2),Na_(2)O and CO_(2) |
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Answer» SOLUTION :basic OXIDES : CAO and ` Na_(2)O` ACIDIC oxides: ` SO_(2) and CO_(2)` |
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| 5821. |
From the electronic configurations Na (2, 8, 1), Mg (2, 8, 2) and Al (2, 8, 3), answer the following questions: What is the number of valence electrons in each element? |
| Answer» SOLUTION :1, 2 and 3 RESPECTIVELY | |
| 5822. |
From the electronic configurations Na (2, 8, 1), Mg (2, 8, 2) and Al (2, 8, 3), answer the following questions: Assign the periods to each element in the periodic table. |
| Answer» SOLUTION :PERIOD 3 | |
| 5823. |
From the electronic configurations Li (2, 1), Na (2, 8, 1) and K (2, 8, 8, 1), answer the following questions: What is the period of Na in the periodic table? |
| Answer» SOLUTION :PERIOD 3 | |
| 5824. |
From the electronic configurations N (2,5), O (2,6) and F (2,7), answer the following questions: What is the valency of each one of N, O and F? |
| Answer» SOLUTION :3, 2, 1 RESPECTIVELY | |
| 5825. |
From the electronic configurations Li (2, 1), Na (2, 8, 1) and K (2, 8, 8, 1), answer the following questions: Formula of sodium sulphate is Na_2SO_4. Write the formula of potassium sulphate. |
| Answer» SOLUTION :`K_2SO_4` | |
| 5826. |
From the discharge tube experiment it was concluded that |
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Answer» MASS of PROTON is in fraction |
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| 5827. |
From the aqueous solutions of NaCl , HCl(g), NH_(3),H_(2)O ,CO_(2),MgCl_(2),C_(6)H_(12)O_(6)select The substancescontaining molecules only . |
| Answer» Solution :`C_(6)H_(12)O_(6)(AQ)` | |
| 5828. |
From the aqueous solutions of NaCl , HCl(g), NH_(3),H_(2)O ,CO_(2),MgCl_(2),C_(6)H_(12)O_(6)select The substances containing ions only . |
| Answer» SOLUTION :NAC,(aq),HCL (aq) , `MgCl_(2)(aq)` | |
| 5829. |
From the aqueous solutions of NaCl , HCl(g), NH_(3),H_(2)O ,CO_(2),MgCl_(2),C_(6)H_(12)O_(6)select The substances containing both molecules and ions. |
| Answer» SOLUTION :`NH_(3)(aq),CO_(2)(aq),H_(2)O(l)` | |
| 5830. |
From left to right in a period, the acidic nature of the oxides of elements |
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Answer» decreases |
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| 5831. |
From left to right in a period, metallic character gradually decreases. |
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Answer» |
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| 5832. |
Fresh milk has a pH of 6. When it changes into curd (yogurt) , will its pH value increase or decreases ? Why ? |
| Answer» SOLUTION :When MILK changes into curd (yougurt) , its pH VALUE DECREASES . This is because during curd formation , LACTIC acid is produced which makes it acidic . | |
| 5833. |
Fresh milk has a pH of 6. How do you think the pH will change as it turns into curd? Explain your answer. |
| Answer» Solution :The PH will FALL below 6. This is because LACTIC acid (an acid) is produced when milk sets into CURD. | |
| 5834. |
Fresh milk has a pH of 6. When it changes into curd (yogurt), will its pH value increase or decrease? Why? |
| Answer» SOLUTION :When MILK CHANGES into curd, its pH will DECREASE. Because curd CONTAINS acid , so `H^+` ion increases and thus pH will decrease. | |
| 5835. |
Fresh milk has a pH of 6. How do you think the pH will change as it turns into curd ? Explain your answer. |
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Answer» Solution :(a) The PH of milk is 6 as it CHANGES to curd , the pH will reduce because curd is ACIDIC in nature .The acids present in it decrease the pH. (B) THEMILKMAN shifts the of the pH, fresh milk from 6 to slighty alkaline because is alkaline condition, milk does not set as curd easily. |
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| 5836. |
Frenkel defect is shown by crystals having ...... coordination number |
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Answer» low |
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| 5837. |
Four students A, B, C and D of Class X measured the pH of the given samples of distilled water, 0.1 M solution of ethanoic acid, 0.1 M solution of hydrochloric acid and 0.1 M solution of sodium hydroxide using pH papers at 298 K. Tell which one of the following represents a correct measurement? |
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| 5838. |
Four students A,B,C and D noted the initial colour of the solutions in beakers I, II, III and IV. After inserting zinc rods in each solution and leaving it undisturbed for two hours, noted the colour of each solution again. They recorded their observations in thr form of a table given below: Which student noted the colour change in all four beakers correctly? |
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Answer» Solution :The student A had recorded the correct observations in all the four beakers. • In beaker I, zinc is not in a position to displace aluminium metal, SINCE it is placed below it. Therefore, the solution would remain COLOURLESS. • In beaker II, zinc is in contact with `ZnSO_(4)`. Therefore, no chemical reaction is possible. The solution would remain colourless. • In beaker III, zinc would displace iron present in ferrous sulphate solution (light green) to form zinc sulphate which is colourless. • In beaker IV, zinc would displace copper from copper sulphate solution (blue) to form zinc sulphate which is colourless. From the above discussion, it is quite CLEAR that the student A had MADE correct observations initially and also after the experiment. |
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| 5839. |
Four set ups a given below were arranged to identify the gasevolved when dilute hydrochloric acid was added to zinc granules. The most apropriate set up is: |
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Answer»
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| 5840. |
Four elements P, Q, R and S have atomic numbers 12, 13, 14 and 15 respectively. Answer the following questions giving reasons : (i) What is the valency of Q ? (ii) Classify these elements as metals and non-metals. (iii) Which of these elements will form the most basic oxide? |
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Answer» <P> Solution :(i) Q has atomic number 13. Thus, it has electronic configuration 2, 8, 3. Therefore, its valency is 3.(ii) Elements P and Q have 2 and 3 electrons respectively in the valence shell. They will have a TENDENCY to lose electrons and are therefore metals. Elements R and S have 4 and 5 electrons respectively in their valence shell. They will have tendency to gain or share the electrons to complete the OCTET. Therefore, R and S are non-metals. (iii) P will form the most BASIC oxide. Only the metals form basic oxide and P is more metallic than Q. |
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| 5841. |
Four elements recently discoveredare placed in the ___________ |
| Answer» SOLUTION :SEVENTH PERIOD | |
| 5842. |
Four elements P, Q, R and S belong to the third period of the Modern Periodic Table and have respectively 1,3,5 and 7 electrons in their outermost shells. Write the electronic configurations of Q and R and determine their valencies. Write the molecular formula of the compound formed when P and S combine. |
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Answer» Solution :Electronic configuration of Q = 2, 8,3 VALENCY of Q = 3 Electronic Configuration of R = 2,8, 5 Valency of R = 8-5 = 3 Electronic configuration of P = 2,8,1 Electronic configuration of S = 2, 8, 7 FORMULA : PS/Nacl |
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| 5843. |
Four elements P, Q, R and S belong to the third period of the Modern Periodic Table and have respectively 1, 3, 5 and 7 electrons in their outermost shells. Write the electronic configurations of Q and R and determine their valencies. Write the molecular formula of the compound formed when P and S combine. |
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Answer» SOLUTION :ELECTRONIC configuration of Q: 2,8, 3 Valency of Q: 3 Electronic configuration of R: 2, 8,5 Valency of R: 8-5 = 3 `UNDERSET(2,8,1)(P) + underset(2,8,7)(S) to PS` |
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| 5844. |
Four elements A, B, C and D have atomic numbers 12, 13, 14 and 15 respectively. Answer the following questions giving reasons : (i) What is the number of valence electrons and valency of D? (ii) Which of them will have largest atomic radii ? (iii) Which of these elements will form the most basic oxide ? |
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Answer» Solution :(i) VALENCE electrons in .D. = 5 and VALENCY of .D. = 3. (ii) .A. will have largest atomic RADII because atomic radius decreases across a period from left to right. (iii) .A. will form the most basic OXIDE as it is most metallic. |
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| 5845. |
Four elements A, B, C and D along with their electronic configuration are given below: Now answer the following questions: (i) Which two elements belong to the same period ? (ii) Which two elements belong to the same group ? (iii) Which element out of A and C is more reactive and why? |
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Answer» Solution :(i) A and B, C and D belong to the same period. (ii) A and C have one valence ELECTRON, so they belong to same GROUP. (III) C is more REACTIVE because C is placed below A in the PERIODIC table and reactivity increases down the group. |
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| 5846. |
Formation of X^(-) ion from 'X' is associated with the release of 144 kJ// mol energy. However, Formation of X^(-2) ion from X^(-) is associated with the absorption of 840 kJ of energy. How do you account for this? |
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Answer» Solution :During the addition of an electron to a neutral atom, work is done towards the NUCLEAR force of ATTRACTION. HENCE, energy is RELEASED. After the addition of an electron, the uninedative species formed, ltbegt repels the 2ND electron. Hence during the addition of the second electron, work is done against the force of repulsion that requires supply of energy. |
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| 5847. |
Formation of vapour from the buring substance is not necessary to produce a flame. |
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| 5848. |
Formation of nitric oxide from nitrogen and oxygen is a_____ reaction . |
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| 5849. |
Formation of ethanol from ethene is called_____(hydration/dehydration). |
| Answer» SOLUTION :HYDRATION | |
| 5850. |
Formaldehyde is used as a…………………. |
| Answer» SOLUTION :DISINFECTANT | |
