Q1.What is the weight of one atom of Hydrogen in grams?
(a) 6.023 × 10–23
(b) 1.66 × 10–24
(c) 6.62 × 10–24
(d) None of these Q2. What is the number of water molecules present in a tiny drop of water (volume 0.0018 ml) at room temperature?
(a) 4.84 × 1017
(b) 4.184 × 1018
(c) 6.023 × 1019
(d) 6.023 × 1023 Q3. Which one among the following statements regarding the properties of mixtures and compounds is not correct?
(a) A mixture shows the properties of its constituents but the properties of a compound are entirely different from its constituents
(b) A mixture may be homogeneous or heterogeneous but a compound is a homogeneous substance
(c) The constituents of a mixture can be separated by physical methods but those of a compound cannot be separated by physical methods
(d) Energy is either absorbed or evolved during the preparation of a mixture but not in the preparation of a compoundQ4. The phenomenon of radioactivity was discovered by
(a) Marie Curie
(b) Pierre Curie
(c) Henri Becquerel
(d) J.J. ThomsonQ5. Following statements are made in connection with carbon dioxide (CO2)
1. CO2 is a poisonous gas.
2. CO2 is an acidic oxide.
3. CO2 turns limewater milky.
Which of the statements given above is/are correct?
(a) 1 and 2
(b) 2 and 3
(c) 3 only
(d) 1 and 3Q6. Why is nitrogen molecule chemically less active?
(a) It has small atomic radius
(b) It has high electronegativity
(c) It has high dissociation energy
(d) It has stable electronic configuration Q7. Aluminium is more reactive than iron but aluminium is less easily corroded than iron, because
(a) oxygen forms a protective oxide layer
(b) it is a noble metal
(c) iron undergoes reaction easily with water
(d) iron forms ionsQ8. Which of the statements given below is/are correct? Permanent hardness of water is due to the presence of soluble.
1. chloride of calcium
2. bicarbonate of calcium
3. sulphate of magnesium
4. bicarbonate of magnesium
Select the correct answer using the codes given below.
(a) 1 only
(b) 1 and 3
(c) 2 and 4
(d) 1, 2 and 3Q9. The acid in gastric juice is
(a) acetic acid
(b) nitric acid
(c) hydrochloric acid
(d) sulphuric acid Q10. What is the purpose of adding plasticizers in paint manufacturing process?
(a) They act as a film-forming constituent
(b) They reduce the viscosity
(c) They prevent the polymerization and condensation
(d) They provide elasticity to the film and minimize its cracking Q11. Which one of the following correctly defines the state of glass?
(a) Crystalline solid
(b) Super cooled liquid
(c) Condensed gas
(d) Liquid crystal Q12. Glass is actually
(a) a crystalline solid
(b) an ionic solid
(c) an elastic solid
(d) a vitrified liquid
1. (b)2. (c)3. (d)4. 5. (c)6. (c)7. (d)8. (b)9. 10. (d)11. (b)12. (c)