Volume Relationships in Chemical Equations Question?

Question

Can someone help me understand how to set up this equation?
Calculate the volume of methane that must decompse to produce 10.0 liters of hydrogen. If the two gases are compared at the same temp and pressure.
CH4(g)----->C(s)+2H2(g)

Answer 1

the equation shows that:
1 molecule of methane decomposes to give 1 molecule of carbon and 2 molecules of hydrogen.

Applying Avogadro's law, which allows us to change from a statement about molecules of gases to the same statement about volumes, we can say;

1 volume of methane decomposes to give 2 volumes of Hydrogen.

2 vols H = 10.0 L
therefore 1 vol CH4 = 10.0 L/ 2 = 5.0 L

the vol of methane must be 5 L

[Avogadro's Law: equal volumes of all gases at the same temp and pressure contain the same no of molecules]

Answer 2

Well, it looks to me that, for every molecule of methane, you get two molecules of hydrogen gas. So I'd say you would need 5 liters of methane.

Answer 3

From the gas law equation, we know that PV=nRT...
PV=nRT.......for methane
PV=nRT........for hydrogen
Divide diz 2 equations....and u will get
Vmethane/Vhydrogen=n(methane)/n(hydrogen)

n=refer no. of mole from the stoichiometric..

so, u will get Vmethane=5 liters