Question

after combustion with excess oxygen, 12.501 g of a petroleum compound made of c and h produced 38.196 g co₂ and 18.752 g h₂o. how many moles of carbon are in the co₂? ? moles c used hint: get the c out of the co₂.

Explanation:

Step1: Find molar mass of \(CO_2\)

Molar mass of \(C\) is \(12.01\space g/mol\), molar mass of \(O\) is \(16.00\space g/mol\). So molar mass of \(CO_2\) is \(12.01 + 2\times16.00 = 44.01\space g/mol\).

Step2: Calculate moles of \(CO_2\)

Moles of \(CO_2=\frac{mass\ of\ CO_2}{molar\ mass\ of\ CO_2}=\frac{38.196\space g}{44.01\space g/mol}\).

Step3: Determine moles of \(C\)

In \(CO_2\), each mole of \(CO_2\) contains 1 mole of \(C\). So moles of \(C\) = moles of \(CO_2\).
Calculating moles of \(CO_2\): \(\frac{38.196}{44.01}= 0.868\space mol\) (approx). So moles of \(C\) is also \(0.868\space mol\) (more precisely, \(\frac{38.196}{44.01}=0.86789\approx0.868\)).

Answer:

\(0.868\) (or more precisely, the value from \(\frac{38.196}{44.01}\) which is approximately \(0.868\) moles)