A volume of #20*cm^3# acetylene was combusted with a volume of #500*cm^3# dioxygen in a piston. What is the end volume of the gases confined by the piston?

1 Answer
Aug 29, 2017

Answer:

Good question......I gets an end volume of #490*cm^3#

Explanation:

We gots the combustion equation.....

#HC-=CH(g) + 5/2O_2(g) rarr 2CO_2(g) +H_2O(l)+Delta#

I use the half-integral coefficient because I think the arithmetic is easier in this way. Is it balanced? It is your problem not mine.

And so we start with #20*cm^3# acetylene, which required #50*cm^3# of dioxygen, and gives #40*cm^3# carbon dioxide gas upon complete combustion. I assume that the water has condensed. Agreed?

And so to begin we had a #(20_"acetylene"+500_"dioxygen")*cm^3# volume of gas.....

To end we had ............ #(520_"starting volume"-50_"dioxygen"-20_"acetylene"+40_(CO_2))*cm^3=490*cm^3#

Do you agree? All care taken but no responsibility admitted.