What mass of hydrogen gas is produced when 3.0 mol of iron react with excess hydrochloric acid according to the reaction below
2Fe + 6HCl --> 2FeCl3 + 3H2
To calculate the mass of hydrogen gas produced when 3.0 mol of iron reacts with excess hydrochloric acid, we first need to determine the stoichiometry of the reaction.
According to the balanced equation, 2 mole of Fe reacts with 6 moles of HCl to produce 3 moles of H2 gas. This means that the mole ratio between Fe and H2 is 2:3.
Now, we can use this ratio to calculate the number of moles of H2 gas produced:
Number of moles of H2 = (Number of moles of Fe) x (Mole ratio of H2 to Fe)
= 3.0 mol x (3 mol H2 / 2 mol Fe)
= 4.5 mol H2
Finally, to find the mass of H2 gas, we need to use the molar mass of hydrogen, which is approximately 2.02 g/mol:
Mass of H2 = (Number of moles of H2) x (Molar mass of H2)
= 4.5 mol x 2.02 g/mol
≈ 9.09 g
Therefore, approximately 9.09 grams of hydrogen gas will be produced when 3.0 moles of iron react with excess hydrochloric acid.