Question

I got that question wrong can someone tell me the answer and why it’s right?

Answer 1

You first need to find the molar mass of ethane to figure this out.

`C_(2)H_(6)=2(12.01)\ +\ 6(1.01)\\C_(2)H_(6)=30.08\ g/mol`

You then need to find the mass of carbon by multiplying its molar mass by how many molecules of carbon there are in the compound.

`C_(2)=2(12.01)\\C_(2)=24.02g`

You then simply divide the mass of carbon by the mass of the entire compound.

`=(C_(2))/(C_(2)H_(6)) \\\\\\=(24.02)/(30.08)\\\\=79.8537234\\`

Multiply this value by 100 to get your percentage.

`=79.8537234\ x\ 100\\`

= 79.85% (round as you wish)