A chemist recorded the following data when three different samples of pure carbon $($C$)$ were burned in air to produce carbon dioxide $($CO$2).$

Initial Mass of Pure Carbon $($grams$)$ Mass of CO$2$ Produced $($grams$)$

Sample $12\mathrm{.}308\mathrm{.}44$

Sample $22\mathrm{.}709\mathrm{.}88$

Sample $32\mathrm{.}208\mathrm{.}06$

$($a$)$ Determine whether the results support the law of constant composition.

The mass ratio of carbon dioxide $($CO$2)$ to pure carbon $($C$)$ for each experiment is $.$ Therefore, the calculations indicate that carbon dioxide composed of fixed proportions of carbon $($C$)$ and oxygen $($O$),$ and this composition the same regardless of the size or source of the sample. Thus, the fixed composition of carbon dioxide the law of constant composition.

$($b$)$ Which postulate of Dalton's atomic theory is supported by the results?

The results support the postulate of Dalton's atomic theory according to which the number and types of atoms in a particular compound are fixed.