Balance the following Equation:

___Zn + ___HCl --> ___ZnCl2 + ___H2

50g of zinc are reacted with 50g of hydrogen chloride. Calculate the amount of hydrogen made.
A: 0.765g

B: 1.5g

C: 1.4 g

D: 0.685g

The amount of hydrogen gas made is 1.4 grams (option C is correct)

Explanation:

Step 1: Data given

Mass of Zinc (Zn) = 50.0 grams

Mass of Hydrogen chloride (HCl) = 50.0 grams

atomic mass Zn = 65.38 g/mol

Molar mass HCl = 36.46 g/mol

Step 2: The balanced equation

Zn + 2HCl → ZnCl2 + H2

step 3: Calculate moles

Moles = mass / molar mass

Moles Zn = 50.0 grams / 65.38 g/mol

Moles Zn = 0.764 moles

Moles HCl = 50.0 grams / 36.46 g/mol

Moles HCl = 1.37 moles

Step 4: Calculate limiting reactant

For 1 mol n we need 2 moles HCl to produce 1 mol ZnCl2 and 1 mol H2

HCl is the limiting reactant. It will completely be consumed (1.37 moles)

Zn is in excess. There will react 1.37/2 = 0.685 moles

There will remain 0.764 -0.685 = 0.079 moles

Step 5: Calculate moles H2

For 1 mol n we need 2 moles HCl to produce 1 mol ZnCl2 and 1 mol H2

For 1.37 moles HCl we'll have 1.37/2 = 0.685 moles H2

Step 6: Calculate mass H2

Mass H2 = 0.685 moles * 2.02 g/mol

MAss H2 = 1.38 grams ≈ 1.4 grams

The amount of hydrogen gas made is 1.4 grams (option C is correct)