The volume of 4.92 grams of hydrogen gas at STP is 55 L.
Step-by-step explanation:
1 mole of an ideal gas will occupy 22.4 L
To find volume, the molar volume of a gas is
22.4 L / 1 mole H 2 → this takes you from moles of H 2 to liters
Now, to find the number of moles present in 4.92 g of hydrogen gas, you can use the gas' molar mass
4.92 g
1 mole H 2 / 2.016 g = 2.44 moles H 2
This sample of hydrogen gas will thus occupy
2.44 moles H 2
22.4 L / 1 mole H 2 = 54.6 L = 55 L.