Can anyone answer these Gas Stoichiometry questions with work?

Question

For these problems : Assume that the reactions are being performed at a pressure of 1.0 atm and a temperature of 298K

1) Calcium carbonate decomposes at high temperatures to form carbon dioxide and calcium oxide: CaCO3 -> CO2+ CaO
How many grams of calcium carbonate will I need to form 3.45 liters of carbon dioxide?

2) Ethylene burns in oxygen to form carbon dioxide and water vapor: C2H4 + 3O2 -> 2CO2 + 2H2O, How many liters of water can be formed if 1.25 liters of ethylene are cosumed in this reaction?

Answer 1

1) Calcium carbonate decomposes at high temperatures to form carbon dioxide and calcium oxide: CaCO3 -> CO2+ CaO
How many grams of calcium carbonate will I need to form 3.45 liters of carbon dioxide?

since this rxn is done at rtp, molar vol of gases = 24L
moles of CO2= 3.45L/24L
=0.14375mol
mol ratio of CaCO3:CO2= 1:1
moles of CaCO3=0.14375mol
mass of CaCO3= 0.14375mol x 100 (mol wt of CaCO3)
= 14.375g

2) Ethylene burns in oxygen to form carbon dioxide and water vapor: C2H4 + 3O2 -> 2CO2 + 2H2O, How many liters of water can be formed if 1.25 liters of ethylene are cosumed in this reaction?

moles of C2H4 = 1.25L/24L
=0.052mol
mol ratio of C2H4:H2O=1:2
moles of water = 0.052 x2 = 0.104mol
vol of water= 0.104 x 24L=2.5L

Answer 2

1) x/(40 + 12 + 48) = 3.45/22.4
x/100 = 3.45/22.4
x = 15.4 g

2) x/36 = 1.25/28
x = 1.61 L before condensation