Question

How many grams of magnesium chloride can be produced if we react 32.50 g Mg with 32.50 g HCl

Answer 1

The mass of magnesium chloride produced is calculated as follows

write the equation for reaction
Mg +2HCl=MgCl +H2
find the moles of each reactant
moles = mass/molar mass
moles for mass = 32.5 g/24.3 g/mol= 1.34 moles
moles for HCl = 32.5g / 95.3 g/mol=0.89 moles

HCl is the limiting reagent hence by use of mole ratio between HCl to MgCl2 which is 2:1 the moles of MgCl2 is therefore = 0.89/2 =0.445 moles

mass of MgCl2 is therefore= moles/molar mass
=0.445moles x 95.3 g/mol= 42.4 grams of MgCl2