How to get magnesium hydroxide starting from magnesium and water? Calculate the mass (g)

| January 9, 2021 | education

How to get magnesium hydroxide starting from magnesium and water? Calculate the mass (g) of the product that will be obtained from 48 (g) magnesium. What is the maximum amount of carbon dioxide that can be absorbed by this amount of magnesium hydroxide?

Mg + 2H2O = Mg (OH) 2 + H2 ↑ (general equation).
Add water to magnesium, heat, MgO is formed.
Mg + H2O = MgO + H2 ↑.
Then add water to the resulting oxide, Mg (OH) 2 is formed.
MgO + H2O = Mg (OH) 2.
Let’s find the amount of Mg substance.
n = m: M.
M (Mg) = 24 g / mol.
n = 48 g: 24 g / mol = 2 mol.
For 1 mol of Mg, there is 1 mol of MgO.
The substances are in quantitative ratios of 1: 1.
The amount of substances will be the same.
n (MgO) = n (Mg) = 2 mol.
Let’s find the mass of MgO.
M (MgO) = 40 g / mol.
m = n × M.
m = 40 g / mol × 2 mol = 80 g.
n (MgO) = n (Mg (OH) 2) = 2 mol.
M (Mg (OH) 2) = 58 g / mol.
m = n × M.
m = 58 g / mol × 2 mol = 116 g.
Mg (OH) 2 + CO2 = MgCO3 + H2O.
For 1 mole of Mg, there is 1 mole of CO2.
The substances are in quantitative ratios of 1: 1.
The amount of substances will be the same.
n (Mg (OH) 2) = n (CO2) = 2 mol.
V = Vn n, where Vn is the molar volume of the gas, equal to 22.4 l / mol, and n is the amount of substance.
V = 2 mol × 22.4 L / mol = 44.8 L.
Answer: 44.8l.



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