Calculate the chemical amount of hydrogen, which is obtained in the reaction of zinc weighing 6.5 g

Calculate the chemical amount of hydrogen, which is obtained in the reaction of zinc weighing 6.5 g with an excess of hydrochloric acid. How much hydrogen is released?

Given:
m (Zn) = 6.5 g

To find:
n (H2) -?
V (H2) -?

Decision:
1) Write the equation of a chemical reaction:
Zn + 2HCl => ZnCl2 + H2 ↑;
2) Using the periodic system of D.I.Mendeleev, calculate the molar masses of Zn and H2, which will be numerically equal to the molecular weights:
Mr (Zn) = Ar (Zn) = 65 g / mol;
Mr (H2) = Ar (H) * 2 = 1 * 2 = 2 g / mol;
3) Calculate the amount of substance Zn:
n (Zn) = m (Zn) / Mr (Zn) = 6.5 / 65 = 0.1 mol;
4) Calculate the amount of substance H2 (taking into account the coefficients in the reaction equation):
n (H2) = n (Zn) = 0.1 mol;
5) Calculate the volume H2:
V (H2) = n (H2) * Vm = 0.1 * 22.4 = 2.24 liters.

Answer: The amount of substance H2 is 0.1 mol; volume H2 – 2.24 l.