Chemistry Miscellaneous Questions

CHEMISTRY

 

1. Which of the following substances can be used for drying of gases:

(A) P₂O₅                                                          (B) H₂SO₄

(C) CaO                                                          (D) All

 

2. 10 g of a piece of marble was put into excess of dilute HCl acid. When the reaction was complete, 1120 cm³ of CO₂ was obtained at STP. The percentage purity of CaCO₃ in the marble is

(A) 25%                                                           (B) 50%

(C) 75%                                                           (D) 100%

 

3. Which of the following aqueous solutions will have the lowest value of freezing point in centrigrade scale?

(A) 1% Urea                                                    (B) 1% Glucose

(C) 1% Sucrose                                              (D) 1% Starch

 

4. H₂O₂ solution used for hair bleaching is sold as solution of approx 5.0 gm H₂O₂ per 100 ml of the solution. The volume strength of the H₂O₂ is

(A) 20                                                              (B) 16.8

(C) 10                                                              (D) 27.5

 

5. The normality of 10% (Wt./Vol.) acetic acid is

(A) 1N                                                             (B) 10N

(C) 1.7N                                                          (D) 0.83 N

 

6. The heat of combustion of ethanol determined in a bomb calorimeter is –670.48 K.Cals mole^–1 at 298 K. What is DE at 298 K for the reaction?

(A) 760.48 K.Cal mole^–1                                 (B) –760.48 K. Cal mole^–1

`           (C) –670.48 K. Cal mole^–1                              (D) +670.48 K. Cal mole^–1

 

7. BeF₂ is a linear molecule and OF₂ is

(A) Linear molecule                                        (B) Bent molecule

(C) Tetrahedral molecule                                (D) Square planer

 

8. Metallic lusture is due to

(A) High density of metal                                (B) Polished surface of metal

(C) Chemical reactivity of metals                   (D) Reflection of light by free electrons

 

9. After 25.0 ml of 0.202M Ca(OH)₂ is mixed with 25.0 ml of 0.288 M HClO₄. What is the concentration of OH^– ions?

(A) 0.116 M                                                     (B) 0.0580 M

(C) 1.45 ´ 10^–3 M                                            (D) 2.90 ´ 10^-2 M

 

10. Blister copper is

(A) Pure copper                                              (B) Ore of copper

(C) Copper containing some impurity            (D) Alloy of copper

 

11. In the electrolysis of alumina it is mixed with cryolite (Na₃AlF₆) and fluorspar (CaF₂) in the ratio 20 : 40 : 20. The function of cryolite and fluorspar is

(A) To dissolve alumina

(B) To increase ionization of alumina

(C) To increase the fusion temperature of alumina

(D) To decrease the fusion temperature of alumina and to make it good conductor of electricity.

12. The properties of lithium are similar to those of Mg. This is because

(A) Both have nearly the same size

(B) The ratio of their charge  to size is nearly the same

(C) Both have similar electronic configuration

(D) Both are found together in nature

 

13. Which of the following does not give flame test?

(A) Sr                                                              (B) Be

(C) Ra                                                             (D) Li

 

14. Metallic magnesium (Mg) is prepared by

(A) Displacement of Mg by iron from MgSO₄ solution

(B) Electrolysis of an aqueous solution of Mg(NO₃)₂

(C) Electrolysis of molten MgCl₂

(D) Reduction of MgO by coke

 

15. At extremely low pressure, the van der Waal’s equation for one mole of a gas may be written as

(A) PV = RT  + Pb                                          (B) PV = RT –

(C) PV = RT                                                    (D)

 

16. The ratio of rates of diffusion of SO₂,O₂ and CH₄ is

(A) 1 :  : 2                                                  (B) 1: 2 : 4

(C) 2 :  : 1                                                  (D) 1 : 2  :

 

17. A box is divided into two equal compartments by a thin partition and they are filled with gases P and Q respectively. The two compartments have a pressure of 250 torr each. The pressure after removing the partition will be equal to.

(A) 125 torr                                                      (B) 2.5 torr

(C) 250 torr                                                     (D) 500 torr

 

18. The hybridization and shape of  will be

(A) sp³d T-shaped                                           (B) sp³d linear

(C) sp³d² trigonal bipyramidal                         (D) sp³d² linear

 

19. Propene is more reactive than ethene towards HBr because

(A) Propene can more readily undergo a free radical chain reaction

(B) Propene gives rise to more stable carbonium ion

(C) The double bond in case of propene is unstable

(D) The methyl group attached to double bond withdraws the electrons and facilitate the attack.

 

20. Which of the following species will be aromatic?

(A)		(B)
(C)		(D)

 

21. meso–(R,S)–2,3–dibromobutane on E₂ reaction forms

(A) Cis –or (Z) –2–bromo–2-butene               (B) trans – or (E) – 2– bromo –2- butene

(C) both A and B                                             (D) None of the above

22. In the Victor – Maeyer’s test for alcohols, the  characteristic colour given by the primary alcohols is

(A) Blue                                                           (B) Green

(C) Red                                                           (D) Purple

 

23. A crystalline solid C₇H₈O reacts with sodium to liberate hydrogen. It is insoluble in water but soluble in dilute aqueous NaOH; upon treatment with Br₂, only one monobrominated compound with the formula C₇H₇OBr was formed. The original compound has the structure

(A)		(B)
(C)		(D)

 

 

24. Boric acid is added to glass, because it

(A) Makes the glass opalescent                     (B)  reduces  the coefficient of expansion

(C) makes the glass brititle                             (D) increases refractive index  of the glass

 

25. In P₄O₆ and P₄O₁₀, the number of oxygen atoms bonded to each phosphrous atomes are respectively

(A) 3 and 3                                                      (B) 4 and 4

(C) 3 and 4                                                      (D) 4 and 3

 

26. When chlorine water is kept in sunlight, oxygen is evolved. Therefore,

(A) affinity of hydrogen for oxygen is less     (B) affinity of hydrogen for oxygen is more

(C) affinity of hydrogen for chlorine is less    (D) hydrogen is a reducing agent

 

27. When a nitrate is boiled with aluminium turnings and concentrated NaOH solution, the gas liberated is

(A) NO₂                                                           (B) NH₃

(C) NO                                                            (D) N₂O

 

28. A compound CuCl has face centered cubic structure. Its density is 3.4 g cm^–3. The length of unit cell is

(A) 5.83Å                                                         (B) 6.783 Å

(C) 7.783 Å                                                     (D) 8.783 Å

 

29. The velocity of electron in the fourth Bohr orbit of hydrogen is v. The velocity of the electron in the first orbit would be

(A) 4v                                                              (B) 16v

(C) v/4                                                             (D) v/16

 

30. The stability of the following alkali metal chlorides follows the order

(A)                          (B)

(C)                          (D)

 

31. 50 ml each of one molar CH₃COOH and 0.50 M NaOH are mixed (Ka for CH₃COOH = 1.8 10^–5). The pH of the mixture is

(A) 6.27                                                           (B) 1.67

(C) 2.67                                                           (D) 4.7447

32. The experimental data for the reaction,

2NO(g) + Cl₂(g) ¾¾® 2NOCl(g) is

Expt.	[Cl2]	[NO]	Initial rate
1.	0.020	0.010	2.40 ´ 10–4
2.	0.020	0.030	2.16 ´ 10–3
3.	0.040	0.030	4.32 ´ 10–3

The reaction is of

(A) first order                                                   (B) second order

(C) third order                                                 (D) zero order

 

33. From the stability constants (hypothetical values), given below, predict which one is the strongest ligand?

(A) Cu²⁺ + 4NH₃  [Cu(NH₃)₄]²⁺, K = 4.5 ´ 10¹¹

(B) Cu²⁺ + 4CN^–  [Cu(CN)₄]^2–, K = 2.0 ´ 10²⁷

(C) Cu²⁺ + 2en  [Cu(en)₂]²⁺, K = 3.0 ´ 10¹⁵

(D) Cu²⁺ + 4H₂O  [Cu(H₂O)₄]²⁺, K = 9.5 ´ 10⁸

 

34. A sample of radon emitted initially 7 ´ 10⁴ alpha particles per second. After some time the emission rate became 2.1 ´ 10⁴. What is the age of the sample? [T_1/2 = 3.8 days)

(A) 6.6 days                                                    (B) 3.3 days

(C) 66 days                                                     (D) 33 days

 

35. Synthetic human hair wigs are made from a copolymer of vinyl chloride and acrylonitrile, and is called

(A) PVC                                                          (B) Polyacrylonitrile

(C) Cellulose                                                   (D) Dynel

 

36. FeCl₃ is applied to stop bleeding because

(A) fe³⁺ ions coagulate blood which is a negatively charged sol.

(B) Cl^– ions cause co-agulation of blood by complexation

(C) FeCl₃ react with the constituents of blood

(D) None of the above

 

37. Glucose when heated with CH₃OH in presence of dry HCl gas a – and b-methyl glycosides are formed. This is because it contains

(A) An aldehydic group                                   (B) –CH₂OH group

(C) A ring structure                                         (D) Five hydroxyl groups

 

38. The formation of cyanohydrin from a ketone is an example of

(A) electrophilic addition                                 (B) nucleophilic addition

(C) nucleophilic substitution                            (D) electrophilic substitution

 

39. The increasing order of boiling points of (A) CH₃COCl (B) (CH₃CO)₂O, (C) CH₃CONH₂ and (D) CH₃COOH

(A) a < d < b < c                                              (B) b < a < c < d

(C) d < a < b < c                                              (D) a < d < b = c

 

40. Which of the following decarboxylate readily in the temperature range 100 – 150°C?

(A) CH₂ = CH — CH₂ — COOH                   (D) O₂N.CH₂COOH

(C) NC.CH₂COOH                                         (D) CH₃COCH₂COOH

 

41. The correct increasing order of basic strength of RCN, RNH₂ and RN=CHR¢ is

(A) RCN, RN = CHR¢, RNH₂                         (B) RCN, RNH₂,RN=CHR¢

(C) RNH₂,RCN,RN=CHR¢                             (D) RN = CHR¢,RNH₂,RCN

42. The dipole moment of o–,m– and p–dichlorobenzene will be in the following decreasing order

(A)  o > p > m                                                  (B) p > o > m

(C) m > o > p                                                   (D) o > m > p

 

43. If the maximum concentration of PbCl₂ in water is 0.01 M at 298 K, its maximum concentration in 0.1 M NaCl will be .

(A) 4 ´ 10^–3 M                                                 (B) 0.4 ´ 10^–4 M

(C) 4 ´ 10^–2 M                                                 (D) 4 ´ 10^–4 M

 

44. The rate constant, the activation energy and the Arrhenius parameter of a chemical reaction at 25°C are 3.0 ´ 10^–4 s^–1, 104.4 kJ mol^–1 and 6.0 ´ 10¹⁴s^–1 respectively. The value of the rate constant as T ® ¥ is

(A) 2.0 ´ 10¹⁸s^–1                                             (B) 6.0 ´ 10¹⁴s^–1

                (C) infinity                                                       (D) 3.6 ´ 10³⁰s^–1

 

45. During transformation of _cX^a to _dY^b, the number of b particles emitted are

(A)                                                          (B)

(C) –c                                            (D) 2c – d  + a – b

 

46. An aqueous solution of HCl is 10^–9 M HCl. The pOH of the solution should be

(A) 9                                                                (B) between 7 and 8

(C) 5                                                                (D) unpredictable

 

47. The maximum efficiency of a steam engine working between 300K and 400K is

(A) 25%                                                           (B) 66.6%

(C) 50%                                                           (D) 75%

 

48. Laughing gas is prepared by heating

(A) NH₄Cl                                                        (B) NH₄NO₂

(C) NH₄Cl + NaNO₃                                       (D) (NH₄)₂SO₄

 

49. HCl, HBr and HI differ markedly in their tendency to give up a proton to the solvent in ethanol but not in water. The effect is termed as

(A) Periodic effect of water                            (B) Neutralizing effect of water

(C) Balancing effect of water                         (D) Levelling effect of water

 

50. F-centres are

(A) the electrons trapped in the anionic vacancies

(B) the electrons trapped in the cation vacancies

(C) non equivalent sites of stoichiometric compounds

(D) All of the above

 

51. What is the radius change of orbits when one electron in hydrogen like species (Z=2) undergoes the first Paschen transition.

(A) 2.11 ´ 10^–10 m                                          (B) 1.85 ´ 10^–10 m

(C) 3.17 ´ 10^–10 m                                          (D) 0.793 ´ 10^–10 m

 

52. Ag₂SO₄ 2Ag⁺ +

A sample of solid silver sulphate was put into a solution originally of 0.02M Na₂SO₄. After the equilibrium is attained, the concentration of silver in the supernatant liquid was 0.04M. If above mentioned reaction is only significant then what is the K_sp value for silver sulphate

(A) 1.6 ´ 10^–3                                                  (B) 8 ´ 10^–4

(C) 6.4 ´ 10^–5                                                  (D) none

53. A near UV proton of 300nm is absorbed by a gas and re-emitted as two photons. One proton is red with wavelength 760nm, the wave number of the second photon in m^–1 is

(A) 2.02 ´ 10¹⁰                                                (B) 2.02 ´ 10^–12

(C) 4.04 ´ 10⁶                                                 (D) 2.02 ´ 10⁶

 

54. One litre of 1M CuSO₄ solution is electrolysed. After passing 2F of electricity molarity of CuSO₄ will be

(A) M/2                                                            (B) M/4

(C) M                                                               (D) 0

 

55. A solution of HCl containing 0.03659g/ml and another solution of acetic acid containing 0.04509 g/ml, then

(A) N HCl  is more                                          (B) N CH₃COOH is more

(C) Both have same N                                    (D) none

 

56. A hydrogen electrode placed in a buffer solution of CH₃COONa and CH₃COOH in the ratio x ; y and y : x has electrode potential values E₁ and E₂ volts respectively at 25°C. The pK_a value of acetic acid is

(A) E₂ – E₁ / 0.118                                          (B) E₁ – E₂ / 0.118

(C) E₁ – E₂ / 0.118                                          (D) –(E₁ + E₂) / 0.118

 

57. Planer geometry is exhibited by

(A) (SiH₃)₃N                                                    (B) AlCl₃

(C) [Ni(CN)₄]^2–                                                (D) All of these

 

58. An unknown compound on oxidative cleavage forms one mole each of cyclopentanone and methanal. The compound is

(A)		(B)
(C)		(D)	None of the above

 

59. Identify Z in the following series

H₂C=CH₂X Y Z

(A) C₂H₅I                                                         (B) C₂H₅OH

(C) CHI₃                                                          (D) CH₃CHO

 

60. The name of [Cr(NH₃)₄Cl₂]NO₃ is

(A) Tetraaminodichlorochromiumnitrate

(B) Tetraaminodichlororochromium(I)nitrate

(C) Tetraaminodichlorochromium (II)nitrate

(D) Dichlorotetraaminechromium(III)nitrate

 

 

 

 

 

 

 

 

 

 

 

 

ANSWERS

 

1. A                                                                     2.         B
2. A                                                                     4.         B
3. C                                                                     6.         C
4. B                                                                     8.         D
5. D                                                                     10.       C
6. D                                                                     12.       B
7. B                                                                     14.       C
8. B                                                                     16.       A
9. C                                                                     18.       b
10. B                                                                     20.       D
11. A                                                                     22.       C
12. A                                                                     24.       B
13. C                                                                     26.       A
14. B                                                                     28.       A
15. A                                                                     30.       A
16. D                                                                     32.       C
17. B                                                                     34.       A
18. D                                                                     36.       A
19. C                                                                     38.       B
20. 39. A                                                                     4       D
21. A                                                                     42.       D
22. 4 D                                                                     44.       B
23. 4 C                                                                     46.       B

47        A                                                                     48.       C

49. D                                                                     50.       A
50. B                                                                     52.       C
51. 5 D                                                                     54.       D
52. 5 A                                                                     56.       C
53. D                                                                     58.       B
54. C                                                                     60.       D

 

 

 

 

 

 

 

 

 

 

HINTS & SOLUTIONS

 

1. Velocity of light is constant.

 

2. 1120 cc CO₂ = 0.05 mole of CO₂ = 0.05 mole of CaCO₃ = 5 gm CaCO₃

% purity  =  = 50%

 

3. Since molecular mass of urea is minimum, the molarity is maximum for urea solution and hence maximum depression in freezing point.

 

5. Strength = 100 gm / litre

N =  = 1.7

 

6. DH = DE + DnRT

 

at extremely low pressure

b << v

 

PV = RT –

8. r µ

 

28. d =

3.4 =

a = 5.783

 

31. CH₃COOH + NaOH ¾¾® CH₃COONa + H₂O

50 m moles    25 mmoles            0

25 m moles       0                         25 m. moles

pH = pK_a + log

= log (1.8 ´ 10^–5) +

= 4.7447 + 0

pH = 4.7447

32. Order with respect to Cl₂

= 1

Order with respect to NO = 2

Overall order of reaction = 2 + 1 = 3

 

33. Greater the value of stability constant stronger the ligand

 

40. b – keto carboxylic acid decarboxylate most easily

PbCl₂ = Pb⁺² + 2Cl^–

43. K_sp = 4S³

4 ´ (.01)³ = 4 ´ 10^–6

K_sp = [Pb⁺²] [Cl^–]²

                4 ´ 10^–6 = [Pb⁺²] [.1]²

[Pb⁺²] = 4 ´ 10^–4

 

44. K =

as T ® ¥

K = Ae°

Or K = A                                                                 

 

 

46. pH of 10^–9 M HCl is between 6 and 7 (since it is very dilute)

Hence pOH will be between 7 and 8.

 

 

51. For 1^st Paschen series

= 109737 bÞ l = 1.85 ´ 10^–10 m

 

52. Ag₂SO₄(s)  +

K_sp = [Ag⁺]²

K_sp = (0.04)² (.04) = 6.4 ´ 10^–5

 

53. E = E₁ + E₂

= +

 

 

 

 

56. pH₁ = pK_a + log  =  = pK_a + log

 

Adding the two equation

 

pK_a =

 

58.

 

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