Consider the following reaction: H2(g) + 2O2(g) --> 2H2O(g)

How many liters of H2O are produced when 15.7 liter of hydrogen are reacted with excess oxygen at STP?

15.7 liters

Explanation: reaction is 2H2 + O2. -> 2H2O

Because all substance still are gases, volumes in

STP conditions are proportional to amount of moles.

Amount of water is same as Hydrogen. Also volume is same.

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%