Water can be decomposed by electrolysis into hydrogen gas and oxygen gas. What mass of water must decompose...

Question

Water can be decomposed by electrolysis into hydrogen gas and oxygen gas. What mass of water must decompose to fill a 4.00 L flask to a total pressure of 2.63 atm at 298 K with a mixture hydrogen and oxygen? (R = 0.08206 L·atm/mol·K)

2 H2O(λ) → 2 H2(g) + O2(g)
a. 27.9 g
b. 7.75 g
c. 6.22 g
d. 11.6 g
e. 5.17 g

Answer 1

c. 6.22 g

Answer 2

2H2O ==> 2H2O + O2 34g H2O2 x (1 mol H2O2 / .34g H2O2) x (1 mol O2 / 2 mol H2O2) = 0.5 mol O2 1 mol of any gas at STP = 22.4L 0.5 mol of any gas at STP = 11.2L Answer is C