The correct option is A 10 V
H2O2 (aq)→H2O (l)+12O2 (g)
Molecular mass of H2O2=34 g mol−1
Moles of H2O2=3434=1 mol
Weight of H2O2 in 1 mL=341120 g
In 1120 mL of solution there is 1 mol of H2O2
So, in 1000 mL of solution, moles of H2O2=1×10001120=100112 mol
1 mol of H2O2 gives 11.2 L of O2 at STP
So,
100112 mol of H2O2 will give 11.2×100112=10 L of O2 at STP
By definition , volume strength of H2O2 is 10 V