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Magnesium metal reacts with sulphur to produce MgS. How many grams of magnesium sulphide can be made from 1.50g of Mg and 1.50g of sulphur by the reaction? Can you find its excess in reactants?
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Posted by
Aamir Sarfraz
Magnesium metal reacts with sulphur to produce MgS. How many grams of magnesium sulphide can be made from 1.50g of Mg and 1.50g of sulphur by the reaction? Can you find its excess in reactants?
The molar mass of Mg is 24.3g and of S is 32.1g.
So, we have 1.50/24.3 = 0.0617mol Mg, and
1.50/32.1 = 0.0467mol S
Sulfur is the limiting reactant, and the thermodynamic equation is therefore
0.0467Mg + 0.0467S = 0.0467MgS
Change in Free Energy: ΔG(100C) = -15.9kJ (negative, so the reaction runs)
Change in Enthalpy: ΔH(100C) = -16.2kJ (negative, so the reaction is exothermic)
The excess Mg is 0.0617 – 0.0467 = 0.015mol, which is 0.015 x 24.3 = 0.365g Mg
The molar mass of Mg is 24.3g and of S is 32.1g.
So, we have 1.50/24.3 = 0.0617mol Mg, and
1.50/32.1 = 0.0467mol S
Sulfur is the limiting reactant, and the thermodynamic equation is therefore
0.0467Mg + 0.0467S = 0.0467MgS
Change in Free Energy: ΔG(100C) = -15.9kJ (negative, so the reaction runs)
Change in Enthalpy: ΔH(100C) = -16.2kJ (negative, so the reaction is exothermic)
The excess Mg is 0.0617 – 0.0467 = 0.015mol, which is 0.015 x 24.3 = 0.365g Mg
Cheers, Liz!
The molar mass of Mg is 24.3g and of S is 32.1g.
So, we have 1.50/24.3 = 0.0617mol Mg, and
1.50/32.1 = 0.0467mol S
Sulfur is the limiting reactant, and the thermodynamic equation is therefore
0.0467Mg + 0.0467S = 0.0467MgS
Change in Free Energy: ΔG(100C) = -15.9kJ (negative, so the reaction runs)
Change in Enthalpy: ΔH(100C) = -16.2kJ (negative, so the reaction is exothermic)
The excess Mg is 0.0617 – 0.0467 = 0.015mol, which is 0.015 x 24.3 = 0.365g Mg
Cheers, Liz!
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