Question

Magnesium metal reacts with hydrochloric acid to produce hydrogen gas H2

Mg + 2HCl ----> MgCl + H2

Calculate the volume (in liters) of hydrogen produced at 33 degrees C and 665 mmHg from 0.0840 mol Mg and excess HCl

P= .875 atm
V= ?
n= .0840 mol
R= 0.0821
T= 306 K

V= nRT/ P

V= .0840 mol (.0821 L atm/ mol K)(306 K)/ .875 atm

V= 2.412 Liters

Is this correct

Answer 1

I would round to 2.41 L since you are allowed only 3 significant figures. Also, I like to see students show that 0.0840 mols Mg = 0.0840 mols H2.

0.0840 mols Mg x (1 mol H2/1 mol Mg) = 0.0840 mol H2.

Answer 2

By the way, you omitted a 2 on MgCl2.