1. Which of the following substances does not have a definite melting point?
a) Bromine
b) Sodium chloride
c) Mercury
d) Glass
Answer: d
2. Among the given nutrients, milk is a poor source of:
a) Calcium
b) Protein
c) Carbohydrate
d) Vitamin C
Answer: d
3. Which scientific law explains the formation of carbon monoxide and carbon dioxide from carbon and oxygen?
a) Law of Conservation of Mass
b) Law of Multiple Proportions
c) Law of Reciprocal Proportions
d) Law of Definite Proportions
Answer: b
4. Which compound has its equivalent weight equal to its molecular weight?
a) H₂SO₄
b) CaCl₂
c) Na₂SO₄
d) NaCl
Answer: a
5. An element X forms an oxide with the formula XO₃. What is the valency of X?
a) 1
b) 2
c) 3
d) 6
Answer: d
6. Which of the following is an example of a chemical change?
a) Crystallization of sodium chloride
b) Melting of ice
c) Sour milk formation
d) All of the above
Answer: c
7. Which of the following is not a mixture?
a) Air
b) Mercury
c) Milk
d) Cement
Answer: b
8. How many electrons are present in a Na⁺ ion?
a) 1
b) 10
c) 11
d) 12
Answer: b
9. Which of the following elements is the poorest conductor of heat?
a) Sodium
b) Lead
c) Zinc
d) Mercury
Answer: b
10. Which of the following is an element?
a) Alumina
b) Brass
c) Graphite
d) Silicon
Answer: c
11. Who proposed that the atom is indivisible?
a) Dalton
b) Berzelius
c) Rutherford
d) Avogadro
Answer: a
12. Which of the following mixtures is homogeneous?
a) Starch and sugar
b) Methanol and water
c) Calcium carbonate and calcium bicarbonate
d) Graphite and charcoal
Answer: b
13. The product of equivalent weight and valency of an element equals its:
a) Vapour density
b) Specific heat
c) Atomic weight
d) Molecular weight
Answer: c
14. ‘Bar’ is the unit of:
a) Pressure
b) Force
c) Energy
d) Frequency
Answer: a