To determine how many moles of hydrogen gas are contained in 21.3 liters (L) at Standard Temperature and Pressure (STP), follow these steps:
1. Understand STP Conditions:
At STP (Standard Temperature and Pressure), 1 mole of an ideal gas occupies 22.4 liters.
2. Given Information:
- The volume of hydrogen gas is 21.3 liters.
3. Use the Molar Volume:
The molar volume at STP (Standard Temperature and Pressure) for an ideal gas is 22.4 liters per mole.
4. Calculate the Number of Moles:
To find the number of moles of hydrogen gas, use the formula:
[tex]\[
\text{moles of gas} = \frac{\text{given volume of gas}}{\text{molar volume at STP}}
\][/tex]
5. Substitute the given values into the formula:
[tex]\[
\text{moles of hydrogen} = \frac{21.3 \, \text{liters}}{22.4 \, \text{liters per mole}}
\][/tex]
6. Calculate:
When you perform the division, you get:
[tex]\[
\text{moles of hydrogen} = 0.9508928571428572
\][/tex]
Therefore, the number of moles of hydrogen gas contained in 21.3 liters at STP is approximately 0.9509 moles.
