In the equation #Mg + 2HCl -> MgCl_2 + H_2#, what volume of hydrogen at STP is produced from the reaction of 50.0 g of #Mg# and the equivalent of 75 g of #HCl#?

1 Answer
Feb 28, 2016

Answer:

#1.03# mol of dihydrogen gas will evolve, with a volume slightly over #22.4# #dm^3# at #STP#.

Explanation:

Moles of magnesium: #(50.0*g)/(24.31*g*mol^-1)# #=# #2.06# #mol#

Moles of hydrogen chloride gas: #(75.0*g)/(36.2*g*mol^-1)# #=# #2.07# #mol#

Given equimolar amounts, clearly, the gas is in deficiency as the stoichiometric equation requires 2 equiv of gas per equiv of metal.

So, the #1# mole of gas evolves, (conveniently, as at #STP# the molar volume is #22.4# #dm^3#).