Page No 33: - Chapter 3 Atoms & Molecules class 9 ncert solutions Science - SaraNextGen [2024-2025]

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On April 24, 2024, 11:35 AM

Question 2:

Hydrogen and oxygen combine in the ratio of 1:8 by mass to form water. What mass of oxygen gas would be required to react completely with 3 g of hydrogen gas?

Answer:

It is given that the ratio of hydrogen and oxygen by mass to form water is 1:8.

Then, the mass of oxygen gas required to react completely with 1 g of hydrogen gas is 8 g.

Therefore, the mass of oxygen gas required to react completely with 3 g of hydrogen gas is 8 × 3 g = 24 g.

Question 3:

Which postulate of Dalton’s atomic theory is the result of the law of conservation of mass?

Answer:

The postulate of Dalton’s atomic theory which is a result of the law of conservation of mass is:

Atoms are indivisible particles, which can neither be created nor destroyed in a chemical reaction.

Question 4:

Which postulate of Dalton’s atomic theory can explain the law of definite proportions?

Answer:

The postulate of Dalton’s atomic theory which can explain the law of definite proportion is:

The relative number and kind of atoms in a given compound remains constant.