Question

How many moles of C are in 122 g of C2H6?

Answer 1

first you'll need to calculate the molecular mass of \(\text C_2\text H_6\)

\[M_{\text C_2\text H_6}=2M_{\text C}+6M_{\text H}\]

then you'll be able to find the number of moles of \(\text C_2\text H_6\) you have

\[n_{\text C_2\text H_6}=\frac {m_{\text C_2\text H_6}}{M_{\text C_2\text H_6}}\]

once you have done this you just need to multiply by two,
because there are two \(\text C\)s for every \(\text C_2\text H_6\)