Gas Stoichiometry

[blstrs]

1. The problem statement, all variables and given/known data

Calcium carbide reacts with water to produce acetylene gas: CaC2 (s) + 2H2O (l) >> Ca(OH)2 (aq) + C2H2 (g). What volume of wet acetylene is collected at 25C and 715 torr when 5.20g CaC2 is reacted with an excess of water? (Vapor pressure of water at 25C = 23.8 torr)



2. Relevant equations

PV=nRT
P(total)=P1+P2...etc


3. The attempt at a solution

I found the moles of "dry" C2H2 (.0811 mol). However, I'm not very sure where vapor pressure and the "wet" comes in...

[Bohrok]

What is the total pressure, Ptotal, of the system? What are the partial pressures?

[blstrs]

Ptotal=715 torr
PH2O=23.8 torr
PC2H2=691.2 torr

I'm still not exactly sure how all of these fit in....

[Borek]

What is volume of acetylene calculated using its partial pressure?

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[_Molly_]

Using the equation PV = nRT, do you recall what P, V, n, R and T stand for? They also need to be in certain units. This may or may not require converting. Do you still need help for this?