Question

Has measured a sample of O2 and has found that she has a total of 18.75 moles of the gas. What is the mass of this sample of oxygen gas? Please round your answer to two digits after the decimal point, and remember to include correct, complete units (including substance formula).

Answer 1

599.96 g O₂

Step-by-step explanation

Given:

Total moles of a sample of O₂ = 18.75 mol

What to find:

The mass of this sample of oxygen gas.

Step-by-step solution:

From the periodic table;

The molar mass of oxygen = 15.999 g/mol

So the molar mass of O₂ gas will be (2 x 15.999 g/mol) = 31.998 g/mol

This implies; 1 mole of O₂ gas has a mass of 31.998 g

So 18.75 moles of O₂ gas will weigh (18.75 x 31.998 g) = 599.9625 g O₂

Therefore, the mass of this sample of oxygen gas to two digits after the decimal point = 599.96 g O₂