Chemistry Miscellaneous Questions
CHEMISTRY
- Which of the following substances can be used for drying of gases:
(A) P2O5 (B) H2SO4
(C) CaO (D) All
- 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%
- 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
- 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
- The normality of 10% (Wt./Vol.) acetic acid is
(A) 1N (B) 10N
(C) 1.7N (D) 0.83 N
- 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
- BeF2 is a linear molecule and OF2 is
(A) Linear molecule (B) Bent molecule
(C) Tetrahedral molecule (D) Square planer
- 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
- 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
- Blister copper is
(A) Pure copper (B) Ore of copper
(C) Copper containing some impurity (D) Alloy of copper
- 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.
- 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
- Which of the following does not give flame test?
(A) Sr (B) Be
(C) Ra (D) Li
- 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
- 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)
- 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 :
- 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
- The hybridization and shape of will be
(A) sp3d T-shaped (B) sp3d linear
(C) sp3d2 trigonal bipyramidal (D) sp3d2 linear
- 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.
- Which of the following species will be aromatic?
(A) | (B) | ||
(C) | (D) |
- 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
- 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
- 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) |
- 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
- 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
- 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
- When a nitrate is boiled with aluminium turnings and concentrated NaOH solution, the gas liberated is
(A) NO2 (B) NH3
(C) NO (D) N2O
- 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
- 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
- The stability of the following alkali metal chlorides follows the order
(A) (B)
(C) (D)
- 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
- 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
- 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
- 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? [T1/2 = 3.8 days)
(A) 6.6 days (B) 3.3 days
(C) 66 days (D) 33 days
- 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
- 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
- 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
- The formation of cyanohydrin from a ketone is an example of
(A) electrophilic addition (B) nucleophilic addition
(C) nucleophilic substitution (D) electrophilic substitution
- 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
- 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
- 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
- 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
- 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
- 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
- During transformation of cXa to dYb, the number of b particles emitted are
(A) (B)
(C) –c (D) 2c – d + a – b
- 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
- The maximum efficiency of a steam engine working between 300K and 400K is
(A) 25% (B) 66.6%
(C) 50% (D) 75%
- Laughing gas is prepared by heating
(A) NH4Cl (B) NH4NO2
(C) NH4Cl + NaNO3 (D) (NH4)2SO4
- 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
- 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
- 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
- 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 Ksp value for silver sulphate
(A) 1.6 ´ 10–3 (B) 8 ´ 10–4
(C) 6.4 ´ 10–5 (D) none
- 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
- 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
- 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
- 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 pKa 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
- Planer geometry is exhibited by
(A) (SiH3)3N (B) AlCl3
(C) [Ni(CN)4]2– (D) All of these
- 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 |
- Identify Z in the following series
H2C=CH2X Y Z
(A) C2H5I (B) C2H5OH
(C) CHI3 (D) CH3CHO
- The name of [Cr(NH3)4Cl2]NO3 is
(A) Tetraaminodichlorochromiumnitrate
(B) Tetraaminodichlororochromium(I)nitrate
(C) Tetraaminodichlorochromium (II)nitrate
(D) Dichlorotetraaminechromium(III)nitrate
ANSWERS
- A 2. B
- A 4. B
- C 6. C
- B 8. D
- D 10. C
- D 12. B
- B 14. C
- B 16. A
- C 18. b
- B 20. D
- A 22. C
- A 24. B
- C 26. A
- B 28. A
- A 30. A
- D 32. C
- B 34. A
- D 36. A
- C 38. B
- 39. A 4 D
- A 42. D
- 4 D 44. B
- 4 C 46. B
47 A 48. C
- D 50. A
- B 52. C
- 5 D 54. D
- 5 A 56. C
- D 58. B
- C 60. D
HINTS & SOLUTIONS
- Velocity of light is constant.
- 1120 cc CO2 = 0.05 mole of CO2 = 0.05 mole of CaCO3 = 5 gm CaCO3
% purity = = 50%
- Since molecular mass of urea is minimum, the molarity is maximum for urea solution and hence maximum depression in freezing point.
- Strength = 100 gm / litre
N = = 1.7
- DH = DE + DnRT
at extremely low pressure
b << v
PV = RT –
- r µ
- d =
3.4 =
a = 5.783
- CH3COOH + NaOH ¾¾® CH3COONa + H2O
50 m moles 25 mmoles 0
25 m moles 0 25 m. moles
pH = pKa + log
= log (1.8 ´ 10–5) +
= 4.7447 + 0
pH = 4.7447
- Order with respect to Cl2
= 1
Order with respect to NO = 2
Overall order of reaction = 2 + 1 = 3
- Greater the value of stability constant stronger the ligand
- b – keto carboxylic acid decarboxylate most easily
PbCl2 = Pb+2 + 2Cl–
- Ksp = 4S3
4 ´ (.01)3 = 4 ´ 10–6
Ksp = [Pb+2] [Cl–]2
4 ´ 10–6 = [Pb+2] [.1]2
[Pb+2] = 4 ´ 10–4
- K =
as T ® ¥
K = Ae°
Or K = A
- pH of 10–9 M HCl is between 6 and 7 (since it is very dilute)
Hence pOH will be between 7 and 8.
- For 1st Paschen series
= 109737 bÞ l = 1.85 ´ 10–10 m
- Ag2SO4(s) +
Ksp = [Ag+]2
Ksp = (0.04)2 (.04) = 6.4 ´ 10–5
- E = E1 + E2
= +
- pH1 = pKa + log = = pKa + log
Adding the two equation
pKa =
58.
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