Question

two gaseous samples were analysed. one contained 1.2g of carbon and 3.2g oxygen. the other contained 27.3/ oxygen. the experimental data are in accordance with

Answer 1

Law of definite proportion

For the first sample, let's calculate the percentages of carbon and oxygen.

Percentage of carbon =

total mass of substance

mass of carbon

×100 =

1.2+3.2

1.2

×100 =

4.4

1.2

×100 =27.27%

Percentage of oxygen =

total mass of substance

mass of oxygen

×100 =

1.2+3.2

3.2

×100 =

4.4

3.2

×100 =72.72%

For the second sample, the percentages of carbon and oxygen are given:

Percentage of carbon =27.3%

Percentage of oxygen =72.7%

Both the samples have an equal percentage of the two elements. This follows law of definite proportions: “In a chemical substance the elements are always present in definite proportions by mass”.