Question

An unknown compound contains only carbon, hydrogen, and oxygen (). Combustion of 7.50 of this compound produced 11.0 of carbon dioxide and 4.50 of water.

1) How many moles of carbon, C, were in the original sample?
An unknown compound contains only carbon, hydrogen, and oxygen (). Combustion of 7.50 of this compound produced 11.0 of carbon dioxide and 4.50 of water.

1) How many moles of carbon, C, were in the original sample?

Answer 1

Firstly, we know that M= m/n,  the main formula which shows the relationship between m, n, and M. The nknown compound contains only carbon, hydrogen, and oxygen, so we can get n(C)=m/M,  from M(C)= m(C)/n (C),  besides the stoechiometric equality, we have

n( C)= m(C)/M(C ) = m(CO2)/ M(CO2)=11/44, because m(CO2)=11.0,  M(CO2)=44.01

so n(C )= 0.24moles,