Question

I. Choose the correct answer.
(5M)
1. Two samples of lead oxide were separately reduced to metallic lead by heating in a
current of hydrogen. The weight of lead from one oxide was half the weight of lead
obtained from the other oxide. The data illustrated
a) Law of reciprocal propositions
b) Law of constant propositions
c) Law of multiple propositions
d) Law of equivalant propositions
2. Chemical equation is balanced according to the law of
a) Multiple proportion
b) Reciprocal proportion
c) Conservation of mass
d) Definite proportion
3. After the chemical reaction, the total mass of reactants and products
a) is always increased
b) is always decreased
c) Is not changed
d) is always less or more
4. Which of the following statements about a compound is incorrect?
a) A molecule of a compound has atoms of different elements
b) A compound cannot be separated into its consituents elements by physical
methods of separation
c) A compound retains the physical properties of its constituent elements.
d) The ratio of atoms of different elements in a compound is fixed.
5. The number of significant figures in the number 1.065
a) 3
b) 4
c) 2
d) 1​

Answer 1

Answer:

1.a

2.c

3.d

4.c

5.b

Explanation:

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