Question #30681

How many grams of magnesium do you need to produce 285 grams of magnesium chloride.
Mg + 2HCl----> MgCl2 + H2

Expert's answer

First of all we can find the amount of substance of magnesium chloride. We can use the formula

n = m/M

where

n - the amount of substance

m - the mass

M - the molar mass, which is calculated: M(MgCl_{2}) = Ar(Mg) + 2* (Cl) = 24 + 2*35.5 = 95g/mol

n(MgCl_{2}) = 285 g / 95 g/mol = 3 moles

According the equation Mg + 2HCl--->MgCl_{2} + H_{2} we can find the amount of substance of magnesium:

n(Mg) = n(MgCl_{2}) = 3 moles

So the mass will be:

m(Mg) = n(Mg)*M(Mg)

M(Mg) = 24 g/mol

m(Mg) = 3 moles * 24 g/mol = 72 g

Answer: 72 g

n = m/M

where

n - the amount of substance

m - the mass

M - the molar mass, which is calculated: M(MgCl

n(MgCl

According the equation Mg + 2HCl--->MgCl

n(Mg) = n(MgCl

So the mass will be:

m(Mg) = n(Mg)*M(Mg)

M(Mg) = 24 g/mol

m(Mg) = 3 moles * 24 g/mol = 72 g

Answer: 72 g

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