Question

Which of the following compounds has the same percentage composition by mass as styrene, $C_8{H}_8$?

• A. Acetylene, $C_2{H}_2$
• B. Benzene, $C_6{H}_6$
• C. Cyclobutadiene, $C_4{H}_4$
• D. All of the above

Answer 1

The correct option is D All of the above

Carbon has a mass of 12 and hydrogen a mass of 1. Work out the % composition of each like this:

In $C_x{H}_x$

total C = $x\times 12=12x$

total H = $x\times 1=x$

So % C = $\frac{12x\times 100}{13x}$

and % H = $\frac{x\times 100}{13x}$

As we see all options are in the form of$C_x{H}_x$ . Hence, percentage composition by mass will be same in all compounds.

Therefore, Option D is correct.