Answer:
The answer is option C
Explanation:
To calculate the mass of oxygen gas we must first find the number of moles of sulphur
Molar mass = number of moles (n) / mass
n = mass / Molar mass
From the question
Molar mass (M) of Sulphur = 32g/mol
mass = 56g
n( Sulphur) = 56/32 = 1.75mol
Since the moles of oxygen and sulphur are the same
M(O2) = 16 × 2 = 32g/mol
Mass of oxygen = molar mass × moles
= 32 × 1.75
Hope this helps you