Question

The amounts of C and O are the same so the empirical formula has equal numbers of C and O atoms; that is, it has the general form CxHyOx. Determine the ratio of H/C (that is, y/x).

Answer 1

Answer:

$\frac{y}{x} =2$

Explanation:

Hello,

In this case, since the subscripts for both carbon and oxygen are equal, one could assume the following empirical formula:

$CH_2O$

Which is suitable for formaldehyde or if it is multiplied by 2 (C₂H₄O₂) for acetic acid or ethen-1,2-diol. In such a way, computing the percent composition:

$\% C=\frac{12}{30}*100 \% =40\%\\\% H=\frac{2}{30}*100 \% =6.67\%\\\% O=\frac{16}{30}*100 \% =53.33\%$

Thus, if at the beginning we just have, the percentages, one could compute moles as:

$n_C=\frac{0.4}{12}=0.0333 \\n_H=\frac{0.0667}{1}=0.0667\\ n_O=\frac{0.5333}{16}=0.033$

Whereas based on the initial formula:

$x=0.0333\\y=0.0667$

The ratio $y/x$ will be:

$\frac{y}{x} =\frac{0.0667}{0.0333}=2$

For all the whole numbers the empirical formula was multiplied by.

Best regards.