Answer: The mass of hydrogen gas formed will be 5.66 g
Step-by-step explanation:
To calculate the number of moles, we use the formula:
.....(1)
For Carbon:
Given mass = 34 g
Molar mass = 12 g/mol
Putting values in above equation, we get:

For the given chemical equation:

By Stoichiometry of the reaction:
1 mole of carbon produces 1 mole of hydrogen gas.
So, 2.83 moles of carbon atom will produce =
of hydrogen gas.
Now, to calculate the mass of hydrogen gas, we use equation 1.
Moles of Hydrogen gas = 2.83 mol
Molar mass of hydrogen gas = 2 g/mol
Putting values in equation 1, we get:

Hence, the mass of hydrogen gas formed will be 5.66 g