Question

How do you determine the mass of carbon dioxide produced when $0.85g$ of butane reacts with oxygen according to the following equation?
$2{C_4}{H_{10}}\, + \,13{O_2}\, \to \,8C{O_2}\, + \,10{H_2}O$

Answer 1

Hint: Here we have reaction of butane ${C_4}{H_{10}}$ with oxygen ${O_2}\,$ so mainly it is a combustion reaction which gives carbon dioxide $C{O_2}\,$ and water. Thus for finding out the amount of carbon dioxide produced from $0.85g$ of butane we first have to find out the amount of carbon dioxide forming according to the reaction.

Complete step-by-step answer:According to the reaction we have $2{C_4}{H_{10}}\, + \,13{O_2}\, \to \,8C{O_2}\, + \,10{H_2}O$ in which if we consider the molar mass of butane, it is $58\,g$ and as there are $2\,moles$ of butane therefore we can say that we have a total of $116\,g$ . So, $116\,g$ of butane is reacting with oxygen and forming carbon dioxide and water. Amount of carbon dioxide is $44g$ as there is a number $8$ in stoichiometry hence, we can say a mass of $352g$ is produced.
Mass of butane $ = \,116g$
Mass of carbon dioxide $ = 352g$
$2{C_4}{H_{10}}\, + \,13{O_2}\, \to \,8C{O_2}\, + \,10{H_2}O$
$116\,g\,of\,{C_4}{H_{10}}\,produces = \,352g\,C{O_2}$
Thus for one gram of butane we will get the amount of carbon dioxide as $1g\,of\,{C_4}{H_{10}}\,produces = \,\dfrac{{352g}}{{116g}}\,C{O_2}$
Now for the amount we want is for $0.85g$ of butane, thus it will be-
$0.85g\,of\,{C_4}{H_{10}}\,produces \left( {\,\dfrac{{352g}}{{116g}}\, \times 0.85} \right)\,C{O_2}$
$ = \,2.579\,g\,C{O_2}$
On solving we get, $2.579\,g$ of carbon dioxide is forming from $0.85g$ of butane.

Note: As we calculated for carbon dioxide, we can easily find out the amount of other substances formed from the reaction of butane and oxygen. The same reaction question can be asked for the amount of water produced and also for the amount of oxygen needed for the reaction. The combustion reactions are when any hydrocarbon reacts with full supply of air oxygen and produces carbon dioxide and water at the end as products.