Term I Exam Revision Test Paper 1 Class XII Subject: Chemistry
Time 1.5 hr Multiple Choice Questions Dated: 30.11.2021 MM 35
1. Mole fraction of glycerin C₃H₅(OH)₅ in solution containing 36 g of water and 46 g of glycerine is
- (a) 0.46
- (b) 0.40
- (c) 0.20
- (d) 0.36
2. An unripe mango placed in a concentrated salt solution to prepare pickle, shrivels because-
- (a) It gains water due to osmosis.
- (b) It loses water due to reverse osmosis.
- (c) It gains water due to reverse osmosis.
- (d) It loses water due to osmosis.
3. Two beakers of capacity 500 mL were taken. One of these beakers, labeled as “A”, was filled with 400 mL water whereas the beaker labeled “B” was filled with 400 mL of 2 M Solution of NaCl. At the same temperature both the beakers were placed in closed containers of same material and same capacity as shown in figure given below :- At a given temperature which of the following statement is correct about the vapour pressure of pure water and that of NaCl solution.
- (a) Vapour pressure in container (A) is more than that in container (B).
- (b) Vapour pressure in container (A) is less than that in container (B).
- (c) Vapour pressure is equal in both the containers.
- (d) Vapour pressure in container (B) is twice the vapour pressure in container (A).
4. When 0.6 g of Urea dissolved in 100 g water, the water will boil at (Kb for water =0.52 K m⁻¹ and normal boiling point of water= 100°C).
- (a) 372.48 K
- (b) 273.52 K
- (c) 373.052 K
- (d) 273.052 K
5. The cell constant of a conductivity cell _____
- (a) Changes with change of electrolyte.
- (b) Changes with change of concentration of electrolyte.
- (c) Changes with temperature of electrolyte.
- (d) Remains constant for a cell.
6. The emf of the cell: Ni / Ni²⁺ (1.0 M) // Au³⁺ (1.0 M) / Au (E° = -0.25 V for Ni²⁺/Ni; E° = 1.5 V for Au³⁺/Au) is
- (a) 1.25 V
- (b) -1.25 V
- (c) 1.75 V
- (d) 2.0 V
7. Standard solution of KNO₃ is used to make a salt bridge because
- (a) Velocity of K⁺is greater than that of NO₃
- (b) Velocity of NO₃ is greater than that of K⁺
- (c) Velocity of both K⁺ and NO₃ ⁻ are nearly same.
- (d) KNO₃ is highly soluble in water.
8. The limiting molar conductivities с┤з°for NaCl, KBr and KCI are 126, 152 and 150 S cm² mol⁻¹ respectively. The с┤з° for NaBr is
- (a) 278 S cm² mol⁻¹
- (b) 128 S cm² mol⁻¹
- (c) 428 S cm² mol⁻¹
- (d) 302 S cm² mol⁻¹
9. Which among the following is a false statement?
- (a) Rate of zero order reaction is independent of initial concentration of reactant.
- (b) Units of rate constant for second order reaction are L mol⁻¹ s⁻¹
- (c) Molecularity of a reaction may be zero or fraction.
- (d) For a first order reaction, t₁/₂=0.693/K
10. An endothermic reaction with high activation energy for the forward reaction is given by the diagram.
Ans : c
11. The rate of a certain hypothetical reaction A + B + C → products is given by- Rate = K[A]¹ٰ/²¹⁴[B]¹/³[C]¹/⁴. The order of the reaction is
- (a) 13/11
- (b) 13/14
- (c) 12/13
- (d) 13/12
12. Milk turns sour at 40oC three times faster than it does at 0oC. This shows that activation energy of souring of milk is
- (a) `\frac{ 2.303 \times R \times 273 \times 313log3}{ 40`
- (b) `\frac{ 2.303 \times R \times 273 \times 313log1/3}{ 40`
- (c) `\frac{ 2.303 \times R \times 273 \times 313log3}{ 40}`
- (d) ) 2.303 x 273 x 313 log3 40
13. 75% of the first order reaction was completed in 32 min. 50% of the reaction was completed in
- (a) 24 min
- (b) 8 min
- (c) 16 min
- (d) 4 min
14. When a small amount of FeCl₃ is added to a freshly precipitated Fe(OH)₃ a reddish brown colloidal solution is obtained. This phenomenon is known as
- (a) Dialysis
- (b) Peptization
- (c) Protection
- (d) Desorption
15. Cottrell precipitator is used to
- (a) Precipitate mud from muddy water.
- (b) Precipitate carbon particles from smoke.
- (c) Purify the ordinary drinking water.
- (d) Precipitate salts in qualitative analysis.
16. A colloidal system is which liquid is dispersed phase and solid is dispersion medium is classified as
- (a) Gel
- (b) Sol
- (c) Emulsion
- (d) Aerosol
17. The formation of micelles takes place only above
- (a) Critical temperature
- (b) Kraft temperature
- (c) Inversion temperature
- (d) Absolute temperature
18. The method of zone refining of metals is based on the principle of
- (a) Greater mobility of the pure metal than that of the impurity.
- (b) Higher melting point of the impurity than that of the pure metal.
- (c) Greater noble character of the solid metal than that of impurity.
- (d) Greater solubility of the impurity in the molten state than in the solid.
19. From the Ellingham graph between Gibb’s energy and temperature, out of C and CO which is a better reducing agent for ZnO?
- (a) Carbon
- (b) CO
- (c) Both of these
- (d) None of these
20. Nitrogen is relatively inert molecule because-
- (a) Its atom has a stable electronic configuration.
- (b) It has low atomic radius.
- (c) Its electronegativity is fairly high.
- (d) Dissociation energy of its molecule is fairly high.
21. Which one of the following is the strongest Lewis base?
- (a) NH₃
- (b) PH₃
- (c) AsH₃
- (d) SbH₃
22. The correct order of acid strength is-
- (a) HClO₄ < HClO₃ < HClO₂ < HClO
- (b) HClO₂ < HClO₃ < HClO₄ < HClO
- (c) HClO₄ < HClO < HClO₃ < HClO₂
- (d) HClO < HClO₂ < HClO₃ < HClO₄
23. The boiling points of hydrides of group 16 are in the order-
- (a) H₂O > H₂Te > H₂S > H₂Se
- (b) H₂O > H₂S > H₂Se > H₂Te
- (c) H₂O > H₂Te > H₂Se > H₂S
- (d) None of these
24. The formation of O₂⁺[PtF₆]⁻ is the basis for the formation of first Xenon compound. This is because-
- (a) O₂ and Xe have different sizes.
- (b) Both O₂ and Xe are gases.
- (c) O₂ and Xe have comparable Electro-negativities.
- (d) O₂and Xe have comparable Ionisation Enthalpies.
25. Oleum is a mixture of-
- (a) H₂SO₄ +SO₂
- (b) H₂SO₄ +SO₃
- (c) H₂S₂O₃ +SO₃
- (d) H₂S₂O₃ +SO₂
26. The element which can displace three other halogens from their compound is-
- (a) F
- (b) Cl
- (c) Br
- (d) I
27. Which of the following compound is not coloured?
- (a) Copper (II) Sulphate
- (b) Zinc (II) Chloride
- (c) Chromium (III) Sulphate
- (d) Manganese (II) Oxallate
28. The maximum magnetic moment shown by the ion with electronic configuration of
- (a) 3d⁸
- (b) 3d⁵
- (c) 3d⁷
- (d) 3d⁹
29. for the reaction CrO₄⁻² + ? →Cr₂O₇⁻² , the missing ion is-
- (a) OH-
- (b) H⁺
- (c) H₂O
- (d) O⁻²
30. The properties of Zr and Hf are similar because-
- (a) Both belong to d-block.
- (b) Both belong to same group of periodic table.
- (b) Both have similar radii.
- (d) Both have same number of electrons.
31. Interstitial compounds are formed when small atoms are trapped inside the crystal lattice of metals. Which of the following is not the characteristic property of interstitial compounds?
- (a) They have high melting points in comparison to pure metals.
- (b) They are very hard
- (c) They retain metallic conductivity
- (d) They are chemically very reactive.
32. When acidified K₂Cr₂O7 solution is added to Sn²⁺+ salts then Sn²⁺ changes to-
- (a) Sn
- (b) Sn³⁺
- (c) Sn⁴⁺
- (d) Sn⁺
33. Why is HCl not used to make the medium acidic in oxidation reactions of KMnO₄ in acidic medium?
- (a) Both HCl and KMnO₄ act as oxidizing agents.
- (b) KMnO₄ oxidises HCl into Cl₂ which is also an oxidizing agent.
- (c) KMnO₄ is a weaker oxidizing agent than HCl.
- (d) KMnO₄ acts as a reducing agent in the presence of HCl.
34. IUPAC name of [Pt(NH₃)₃ Br (NO₂) Cl] Cl is
- (a) triamminechlorodibromidoplatinum (IV) chloride
- (b) triamminechloridobromidonitrochloride- platinum (IV) chloride
- (c) triamminebromidochloridonitroplatinum (IV) chloride
- (d) triamminenitrochlorobromoplatinum (IV) chloride
35. The stabilization of coordination compounds due to chelation is called the chelate effect. Which of the following is the most stable complex species?
- (a) [Fe(CO)]
- (b) [Fe(CN)₆]³⁻
- (c) [Fe(C₂O₄)3]³⁻
- (d) [Fe(H₂O)₆]³⁺
