H2O became a vapor when heated because thats the only one that can go back to its normal state, which is what a physical change is.
Answer: 323.61 g of
will be produced
Explanation:
The given balanced chemical reaction is :

According to stoichiometry :
2 moles of
require 1 mole of 
Thus 3.00 moles of
will require=
of 
Thus
is the limiting reagent as it limits the formation of product.
As 2 moles of
give = 2 moles of 
Thus 3.00 moles of
give =
of 
Mass of 
Thus 323.61 g of
will be produced from the given moles of both reactants.
Answer:
See explanation
Explanation:
The reaction equation is;
C3H8 (g) + 5O2(g) -------> 4H2O(g) + 3CO2(g)
From the formula;
Total enthalpy of reactants = (ΔHf of Reactant 1 x Coefficient) + (ΔHf of Reactant 2 x Coefficient)
Total enthalpy of products= (ΔHf of Product 1 x Coefficient) + (ΔHf of Product 2 x Coefficient)
Hence;
Total enthalpy of reactants =[(-103.85 * 1) + (0 * 5)] = -103.85 + 0 = -103.85 KJ/mol
Total enthalpy of products= [(-393.51 * 4) +(-241.82 * 3)] = (-1574.04) + (-483.64) = -2057.68 KJ/mol