Question

Magnesium metal reacts with hydrochlroic acid according to following reaction:
Mg(s) + 2HCl(aq) -> MgCl2(aq) + H2 (g)
over interval of 10.00s, the mass of Mg changes by -0.22g. What is the corresponding rate of consumption of HCl (in Mol/s) ?

So what i think i should do is first convert the rate of consumption to mol/s and then use that to find corresponding rate of consumption of HCl

This is my work

Molar mass of Mg= 24.3
m=-0.22
n=m/M
n=-0.22/24.3 = -0.009 mol

-0.009 is in 10 seconds so
-0.009/10=-0.0009 mol/s

The ratio between Mg and HCl is 1:2
so

2(-0.0009)=-0.0018 Mol/s

So the rate of consumption of HCl is -0.0018 Mol/s

am i doing anything wrong?

Thanks

Answer 1

It looks ok to me. The negative sign is right but I think a consumption of -0.0018 is redundant. I believe the way to state it is a consumption of 0.0018 mol/s.

Answer 2

Oh okay. thanks a lot :)

Answer 3

i don't know the answer