Chemistry Question

[Sophie]

Can anyone explain to me how to solve this question? The correct answer is D, by the way.
Also, I would like to know if this type of question will be on the IMAT!

The gases X and Y react with each other to produce gas Z according to the equation:

2X(g) + Y(g) → 2Z(g)

100 cm3 of X was mixed with 10 cm3 of Y, in a freely moving gas syringe sealed with a rubber cap. The reaction went to completion. All volumes were measured at the same temperature and pressure.

What is the final volume of gas in the syringe?

A 20 cm3
B 55 cm3
C 80 cm3
D 100 cm3
E 110 cm3
F 120 cm3

[Juliette]

Hi!

Y is the limitant, so when 10cm³ of Y are fully consumed, 20 cm³ of X are used and 20cm³ of Z are formed.
We end up with Vf = 100-20 + 0 + 20 = 100

This topic doesn’t come up very often, but it was in IMAT 2017 Q 46