Simple equation liquid hydrogen peroxide decomposing

Question

If 10.0 grams of liquid hydrogen peroxide decomposes to form liquid water and oxygen gas, how many liters of oxygen gas will there be at STP conditions?

the equation i got is: 2H2O2 (l) >> 2H2O (l) O2 (g)

then i just used molar ratio, since the ratio is 2:1, divided the 10 by 2 and got an answer of 5L...is the answer correct? Are my phases of matter correct? Also, is this a decomposition reaction?

Answer 1

Moles H2O2 = 10.0 g /34.0148 g/mol =0.294

moles O2 = 0.294/2 =0.147

0.147 x 22.4 =3.29 L