Answer
The mass of 0.909 mol $H_{2}$$O_{2}$ is 30.9 g.
Work Step by Step
We are required to convert moles of $H_{2}$$O_{2}$ into grams. So the conversion factor would be : $\frac{Molar mass}{1 mol }$
Molar mass of $H_{2}$$O_{2}$ = 2 x AM H + 2 x AM O
Molar mass of $H_{2}$$O_{2}$ = 2 x 1.007 + 2 x 15.999
Molar mass of $H_{2}$$O_{2}$ = 34.012 g
To convert 0.909 mol $H_{2}$$O_{2}$ we multiply this number with the conversion factor:
0.909 mol x $\frac{34.012 g}{1 mol_{H_{2}O_{2}}}$ = 30.9169 g
To three significant numbers, the mass of 0.909 mol $H_{2}$$O_{2}$ is 30.9 g.
