if 20g of magnesium react with excess hcl how many grams og mgcl2 will be produced
To determine the number of grams of MgCl2 produced in the reaction between 20g of magnesium and excess HCl, we need to use stoichiometry.
1. Write the balanced chemical equation for the reaction:
Mg + 2HCl -> MgCl2 + H2
The stoichiometry of the equation tells us that 1 mole of magnesium (Mg) reacts with 2 moles of hydrochloric acid (HCl) to produce 1 mole of magnesium chloride (MgCl2) and 1 mole of hydrogen gas (H2).
2. Calculate the molar mass of magnesium (Mg) and magnesium chloride (MgCl2):
Molar Mass of Mg = 24.31 g/mol
Molar Mass of MgCl2 = 95.21 g/mol (24.31 g/mol for Mg + 70.9 g/mol for Cl)
3. Determine the number of moles of Mg:
Number of Moles = Mass / Molar Mass
Number of Moles of Mg = 20 g / 24.31 g/mol ≈ 0.822 moles (rounded to 3 decimal places)
4. Use the stoichiometry of the balanced equation to find the moles of MgCl2 produced:
According to the balanced equation, 1 mole of Mg produces 1 mole of MgCl2.
Therefore, the number of moles of MgCl2 produced is also 0.822 moles.
5. Calculate the mass of MgCl2 produced:
Mass = Number of Moles * Molar Mass
Mass of MgCl2 = 0.822 moles * 95.21 g/mol ≈ 78.2 grams (rounded to 1 decimal place)
Therefore, approximately 78.2 grams of MgCl2 will be produced when 20 grams of magnesium react with excess HCl.