Explanation:
2. 
First, we need to find the number of moles of
at 300K and 1.5 atm using the ideal gas law:


Now use the molar ratios to find the number of moles of ethane to produce this much
.


Finally, convert this amount to grams using its molar mass:


3. 
Convert 75 g Zn into moles:

Then use the molar ratios to find the amount of H2 produced.

Now use the ideal gas law
to find the volume of H2 produced at 23°C and 4 atm:

