Chapter 3: Atoms and Molecules- Exercise- 33

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Chapter 3: Atoms and Molecules

Class: IX

Exercise number 33

 

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 3g of hydrogen gas?

Answer 2

It is given that, the ratio of hydrogen and oxygen by mass = 1:8.

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

Therefore, the mass of oxygen  required to completely react with 3g of hydrogen gas

=  8 × 3g = 24 g.

Question 3

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

Answer 3

The Dalton's second postulate "Atoms are indivisible particles, which can neither be created nor be destroyed in a chemical reaction" is the result of the law of conservation of mass.

Question 4

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

Answer 4

The Dalton's postulate "The relative number and kind of atoms in a given compound remains constant" can explain the law of definite proportions.