Question

Magnesium metal reacts with hydrochloric acid to produce hydrogen gas and a solution of magnesium chloride. Write and balance the chemical equation for this reaction, and determine the volume of the hydrogen gas generated (at 1.00 atm, 25 °C) by reacting 10.0 g Mg with an excess of hydrochloric acid

Answer 1

Mg + 2 HCl ⇒ MgCl₂ + H₂

10.1 L

Step-by-step explanation:

Step 1: Write the balanced equation

Mg + 2 HCl ⇒ MgCl₂ + H₂

Step 2: Calculate the moles corresponding to 10.0 g of Mg

The molar mass of Mg is 24.31 g/mol.

10.0 g × 1 mol/24.31 g = 0.411 mol

Step 3: Calculate the moles of H₂ produced from 0.411 moles of Mg

The molar ratio of Mg to H₂ is 1:1. The moles of H₂ produced are 1/1 × 0.411 mol = 0.411 mol

Step 4: Calculate the volume occupied by 0.411 moles of H₂

0.411 moles of H₂ are at 1.00 atm and 25 °C (298 K). We can calculate the volume occupied using the ideal gas equation.

P × V = n × R × T

V = n × R × T / P

V = 0.411 mol × (0.0821 atm.L/mol.K) × 298 K / 1.00 atm = 10.1 L