Carbon combines with hydrogen to forom three compounds `A, B` and `C`. The percentage of hydrogen in `A, B` and `C`.is 25, 14.3, and 7.7, respectively. (a) Find the empirical formula of the compounds. (b) Which law of chemical combination does this example illustrate? How?

Explanation

a. `{:("Element",A,B,C),(Carbon,75%,85.7%,92.3%),(Hydrozen,25%,14.3%,7.7%):}`
Carbon:Hydrogen `(75)/(12):(25)/(1)` `(85.7)/(12)` `(14.3)/(1)` `(92.3)/(12):(77)/(1)`
or `6.25 : 25` `7.14 : 14.3` `7.7 : 7.7`
or `1 : 4` `1 : 2` `1 : 1`
`[{:("Empirical"),("formula"):}] CH_(4), CH_(2), CH`
b. Since the number of `H` atoms or the weights of `H` that combine with one atom or 12 parts by weight of carbon in the three cases bear a simple ratio of `4 : 2 : 1`, hence the law of multiple propertions is illustrated.