Option (b) is the correct answer.
Explanation:
STP means standard temperature and pressure. At this condition pressure is 1 atm, volume is 22.4 L and temperature is 298 K.
Therefore, using ideal gas equation we will calculate the number of moles as follows.
PV = nRT
![1 atm \times 22.4 L = n \times 0.0832 Latm K^{-1}mol^{-1} \times 298K](/tpl/images/0502/5141/9f628.png)
n = 0.903 mol
= 1 mol (approx)
Hence, it is known that molar mass of hydrogen molecule is 2 g/mol. Therefore, calculate mass of
at STP as follows.
Number of moles = ![\frac{mass}{molar mass}](/tpl/images/0502/5141/5ded5.png)
1 mol = ![\frac{mass}{2.02 g/mol}](/tpl/images/0502/5141/2b6f1.png)
mass = 2.02 g
Thus, we can conclude that the mass of 22.4 L of H2 at STP is 2.02 grams.