Question

$64g$of oxygen gas contains ___ moles of oxygen atoms.

Answer 1

Step 1: Definition of a mole

1. A mole is a unit that represents the amount of substance in the unit of moles.
2. One mole of a substance is equal to its relative mass.

Step 2: Calculating the number of moles

From the given data,

1. Mass of oxygen = $64g$
2. The atomic mass of oxygen = $16u$

Applying the value to the equation,

Number of moles = (Given mass/Molar mass)

Number of moles = $\begin{array}{rcl}& & \frac{64\mathrm{g}}{16\mathrm{g}/\mathrm{mol}}\end{array}$ = $\begin{array}{rcl}& & 4\mathrm{mol}\end{array}$

Hence, $64g$ of oxygen gas contains $4$ moles of oxygen atoms.