To calculate the number of moles of [tex]\( \text{H}_2 \)[/tex] molecules in [tex]\( 4 \, \text{g} \, \text{H}_2 \)[/tex], we can follow these steps:
1. Identify the given data:
- Mass of [tex]\( \text{H}_2 \)[/tex] ([tex]\( m_{\text{H}_2} \)[/tex]): [tex]\( 4 \, \text{g} \)[/tex]
- Molar mass of [tex]\( \text{H}_2 \)[/tex] ([tex]\( M_{\text{H}_2} \)[/tex]): [tex]\( 2 \, \text{g/mol} \)[/tex]
2. Recall the formula to calculate the number of moles:
[tex]\[
\text{Number of moles} = \frac{\text{Mass of the substance}}{\text{Molar mass of the substance}}
\][/tex]
3. Substitute the given values into the formula:
[tex]\[
\text{Number of moles of } \text{H}_2 = \frac{4 \, \text{g}}{2 \, \text{g/mol}}
\][/tex]
4. Perform the division:
[tex]\[
\text{Number of moles of } \text{H}_2 = 2
\][/tex]
Thus, the number of moles of [tex]\( \text{H}_2 \)[/tex] molecules in [tex]\( 4 \, \text{g} \, \text{H}_2 \)[/tex] is 2.0.
