Which is the correct equation for the reaction of magnesium with hydrochloric acid to produce hydrogen and magnesium chloride? a. mg + 2 hcl → h2 + mgcl2 b. mg + hcl → h + mgcl c.2 mg + 6 hcl → 3 h2 + 2 mgcl2 d. mg + 2 hcl → 2 h + mgcl2 e. mg + 3 hcl → 3 h + mgcl2?

he would use the colour black

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2