Answer:
9.7 g
Step-by-step explanation:
From the question,
Note: The molar volume of all gas at stp is 22.4 dm³ or 22.4 L
1 mol of oxygen gas (O₂) at stp = 22.4 dm³
X mole of oxygen gas (O₂) at stp = 6.8 L
X = (1 mol×6.8 L)/22.4 L
X = 0.3036 mol.
But,
Number of mole (n) = mass (m)/molar mass (m')
n = m/m'
m = n×m'.................. Equation 2
Where n = 0.3036 mol, m' = 32 g/mol
Substitute into equation 2
m = 0.3036×32
m = 9.7 g