1) Reaction:
Mg(s) + 2HCl (aq) ----> H2(g) + MgCl2(aq)
2) Analysis
An increase in pressure affects directly the rate of reaction involving reactiong gases. Changing the pressure where there are only solids or liquids does not affect the rate of reaction.
This reaction is not an equilibrium, the reaction is only forward. So, the reacting components, Mg(s) and HCl(aq) are a solid and a liquid.
Therefore, the reaction is not affected by the change in pressure.
Answer: the reaction is not affected at all.
Remember that in this case pressure is equal to 1.00 atm and temperature is equal to 273.15K. So,
P
V
=
n
R
T
→
n
=
P
V
R
T
=
1.00
a
t
m
⋅
7.0
L
0.082
a
t
m
⋅
L
m
o
l
⋅
K
⋅
273.15
K
=
0.31
Since we know hydrogen's molar mass (
2.0
g
m
o
l
), we can determine the mass
m
H
2
=
n
⋅
m
o
l
a
r
.
m
a
s
s
=
0.31
m
o
l
e
s
⋅
2.0
g
m
o
l
=
0.62
g
If indeed you are dealing with STP, remember that, under these conditions, 1 mole of any ideal gas occupies
22.4
L
. So,
n
=
V
V
m
o
l
a
r
=
7.0
L
22.4
L
=
0.31
moles
And, once again,
m
=
0.31
⋅
2.0
=
0.6
Answer:
Two, I'd say, unless there's some trick to what you're asking! :)
Explanation:
Carbon dioxide leaves as a product of respiration
