Beginning with 84.0 g of cah2 and 42.0 g of h2o, what volume of h2 will be produced at 273 k and a pressure of 1463 torr?

46.4 L

Explanation:

We must first calculate the amount of H₂ and then calculate its volume.

We have the masses of two reactants, so this is a limiting reactant problem.  

We know that we will need a balanced equation with masses, moles, and molar masses of the compounds involved.  

Step 1. Gather all the information in one place with molar masses above the formulas and masses below them.  

:             42.09   18.02                      2.016

Mass/g:   84.0    42.0  

Step 2. Calculate the moles of each reactant  

Step 3. Identify the limiting reactant  

Calculate the moles of H₂ we can obtain from each reactant.  

From CaH₂:  

From O₂:

The limiting reactant is CaH₂ because it gives the smaller amount of H₂.

Now, we use the Ideal Gas Law to calculate the volume.

pV = nRT

Divide both sides by p.