Answer:
141.89 dm^3
Explanation:
The equation of the reaction is;
2H2O2(aq) --------->2H2O(l) + O2(g)
Now , we are told that the mass of hydrogen peroxide decomposed was 315g. Number of moles of hydrogen peroxide in 315g of the substance is given by;
Number of moles= mass/molar mass
Molar mass of hydrogen peroxide= 34.0147 g/mol
Number of moles= 315g/34.0147 g/mol = 9.26 moles of hydrogen hydrogen peroxide.
From the reaction equation;
2 moles of hydrogen peroxide yields 1 mole of oxygen
9.26 moles of hydrogen peroxide yields 9.26 ×1/2 = 4.63 moles of oxygen
From the ideal gas equation;
Volume of the gas V= the unknown
Pressure of the gas P= 0.792 atm
Temperature of the gas= 23°C +273 = 296 K
Number of moles of oxygen = 4.63 moles of oxygen
R= 0.082atmdm^3K-1mol-1
Hence, from PV=nRT
V= nRT/P
V= 4.63 × 0.082 × 296/0.792 = 141.89 dm^3
