chem help...?

Question

i got the balance part but i do not know how to get the second can you please tell me what to do and the answers to check if it is right

Hydrogen cyanide is prepared commercially by the reaction of methane, CH4(g), ammonia, NH3(g), and oxygen, O2(g), at high temperature. The other product is gaseous water.
(a) Write a chemical equation for the reaction. (Type your answer using the format CO2 for CO2. Use the lowest possible coefficients.)
2CH4(g) + 2NH3(g) +3 (O2 g)2HCN(g) + 6H2O(g)

(b) What volume of HCN(g) can be obtained from 70.0 L CH4(g), 70.0 L NH3(g), and 70.0 L O2(g)? The volumes of all gases are measured at the same temperature and pressure.

Answer 1

To get to your answer, you need to do three different solutions.

Since gas volumes are proportional to moles of each, you can just use the coefficients of the equation to determine the volume of HCN formed from each starting substance. So, for CH4,
70 L ( 2 L HCN/2 L CH4) = 70 L HCN

Then, for the others,
70 L NH3 (2/2) = 70 L HCN

and
70 L O2 (2 L HCN/3 L O2) = 70/3 L HCN.

So, oxygen is the limiting reactant and determines the volume of HCN you can get...