Introduction:
The Law of Reciprocal Proportions, also known as the Law of Multiple Proportions, states that "when two elements combine to form more than one compound, the masses of one element that combine with a fixed mass of the other element are in a ratio of small whole numbers." This law helps to determine the relative atomic masses of elements.

Carbon dioxide:
Carbon dioxide (CO2) contains 27.27% of carbon. The molecular formula of carbon dioxide is CO2, which means that one carbon atom combines with two oxygen atoms. The relative atomic mass of carbon is 12.01 g/mol, and the relative atomic mass of oxygen is 16.00 g/mol. Therefore, the mass ratio of carbon to oxygen in carbon dioxide is 12.01:32.00. Simplifying this ratio gives 3:8. This means that for every 3 grams of carbon in carbon dioxide, there are 8 grams of oxygen. This is a small whole number ratio, which agrees with the Law of Reciprocal Proportions.

Carbon disulphide:
Carbon disulphide (CS2) contains 15.79% of carbon. The molecular formula of carbon disulphide is CS2, which means that one carbon atom combines with two sulphur atoms. The relative atomic mass of carbon is 12.01 g/mol, and the relative atomic mass of sulphur is 32.07 g/mol. Therefore, the mass ratio of carbon to sulphur in carbon disulphide is 12.01:64.14. Simplifying this ratio gives 3:16. This means that for every 3 grams of carbon in carbon disulphide, there are 16 grams of sulphur. This is also a small whole number ratio, which agrees with the Law of Reciprocal Proportions.

Sulphur dioxide:
Sulphur dioxide (SO2) contains 50% of sulphur. The molecular formula of sulphur dioxide is SO2, which means that one sulphur atom combines with two oxygen atoms. The relative atomic mass of sulphur is 32.07 g/mol, and the relative atomic mass of oxygen is 16.00 g/mol. Therefore, the mass ratio of sulphur to oxygen in sulphur dioxide is 32.07:32.00. Simplifying this ratio gives 1001:1000. This means that for every 1001 grams of sulphur in sulphur dioxide, there are 1000 grams of oxygen. This is also a small whole number ratio, which agrees with the Law of Reciprocal Proportions.

Conclusion:
The mass ratios of carbon to oxygen in carbon dioxide, carbon to sulphur in carbon disulphide, and sulphur to oxygen in sulphur dioxide are all small whole number ratios, which agrees with the Law of Reciprocal Proportions. Therefore, these figures are in agreement with the Law of Reciprocal Proportions.