How to Find Net Amount of Gas Produced? - Pre-Class Assessment [ENDORSED]

[Sophia Diaz - Dis 1B]

During a summer camping weekend, 4 moles of butane (C4H10) gas were used for cooking. Choose the right balanced equation for the combustion of 4 moles of butane gas. What is the net number of moles of gas produced?

A. 4 C4H10(g) + 26 O2(g) ----> 16 CO2(g) + 20 H2O(g); 6
B. 4 C4H10(g) + 26 O2(g) ----> 16 CO2(g) + 18 H2O(g); 4
C. 4 C4H10(g) + 25 O2(g) ----> 16 CO2(g) + 20 H2O(g); 6
D. 4 C4H10(g) + 26 O2(g) ----> 16 CO2(g) + 20 H2O(g); 5

I was able to balance the equation to:
4 C4H10(g) + 26 O2(g) ----> 16 CO2(g) + 20 H2O(g) so I know its either A or D.
But, from this point, I have no idea how to solve for the about of moles of gas produced. Am I supposed to simplify coefficients or compare ratios or maybe add something? So basically, how do I solve for the amount of gas produced

[Josian1A]

The problem asks for the net production of gas, and both reactants and products are gases. So all you have to do is: (sum of coefficients from products) - (sum of coefficients from reactants) = net number of moles produced. So you should have 36-30=6 (A)