Answer:
Mass of gas = 0.33 g
Explanation:
Given data:
Mass of magnesium = 23 g
Mass of HCl = 12 g
Mass of MgCl₂ produced = 30 g
Mass of hydrogen gas produced = ?
Solution;
Chemical equation:
Mg + 2HCl → MgCl₂ + H₂
Number of moles of Mg:
Number of moles = mass/molar mass
Number of moles = 23 g/ 24 g/mol
Number of moles = 0.96 mol
Number of moles of HCl:
Number of moles = mass/molar mass
Number of moles = 12 g/ 36.5 g/mol
Number of moles = 0.33 mol
Now we will compare the moles of Hydrogen gas with both reactant.
Mg : H₂
1 : 1
0.96 : 0.96
HCl : H₂
2 : 1
0.33 : 1/2×.33= 0.165 mol
The number of moles of hydrogen gas produced by HCl are less so it will limiting reactant and limit the yield of gas,.
Mass of H₂:
Mass = number of moles × molar mass
Mass = 0.165 mol × 2 g/mol
Mass = 0.33 g
