Question

Hydrogen peroxide was catalytically decomposed and 75.3 mL of oxygen gas was collected over water at 25°C and 742 torr. What mass of oxygen was collec

Answer 1

Answer:

0.0928 grams of oxygen was collected.

Explanation:

Volume of oxygen gas collected = V= 75.3 mL = 0.0753 L (1 mL = 0.001 L)

Temperature of the gas = T = 25°C = 25+ 273 k = 298 K

Pressure of the gas = P - $P_w$= 742 Torr - 24 Torr = 718 Torr

1 atm = 760 Torr

$718 Torr=\frac{718}{760} atm=0.945 atm$

Moles of oxygen gas = n

Using an ideal gas equation;

$PV=nRT\\n=\frac{PV}{RT}$

$n=\frac{0.945 atm\times 0.0753 L}{0.0821 atm L/mol K\times 298 K}$

n = 0.0029 mol

Mass of 0.0029 moles of oxygen gas :

0.0029 mol × 32 g/mol = 0.0928 g

0.0928 grams of oxygen was collected.