Answer:

Explanation:
Hello,
In this case, given the amounts of water and carbon dioxide we should invert the given reaction as hydrogen will be producted rather than consumed:

Consequently, the equilibrium constant is also inverted:

In such a way, we can now propose the law of mass action:
![Kc'=\frac{[H_2][CO_2]}{[H_2O][CO]}](https://tex.z-dn.net/?f=Kc%27%3D%5Cfrac%7B%5BH_2%5D%5BCO_2%5D%7D%7B%5BH_2O%5D%5BCO%5D%7D)
And we can express it in terms of the initial concentrations of the reactants and the change
due to the reaction extent:
![Kc'=\frac{(x)(x)}{([H_2O]_0-x)([CO]_0-x)}=1.87](https://tex.z-dn.net/?f=Kc%27%3D%5Cfrac%7B%28x%29%28x%29%7D%7B%28%5BH_2O%5D_0-x%29%28%5BCO%5D_0-x%29%7D%3D1.87)
Thus, we compute the initial concentration which are same, since equal amount of moles are given:
![[H_2O]_0=[CO]_0=\frac{0.680mol}{70.0L}=0.0097M](https://tex.z-dn.net/?f=%5BH_2O%5D_0%3D%5BCO%5D_0%3D%5Cfrac%7B0.680mol%7D%7B70.0L%7D%3D0.0097M)
Hence, solving for
by using the quardratic equation or solver, we obtain:

For which the correct value is 0.00561M since the other one will produce negative concentrations of water and carbon monoxide at equilibrium. Therefore, the number of moles of hydrogen at equilibrium for the same 70.0-L container turn out:

Best regards.
<span>The question says,'salt is the product formed by a reaction in which .............atoms of an acid are replaced by the atoms of a metal. The correct answer is hydrogen atoms. Salts are formed as a result of the hydrogen ions in the acid been replaced by metal ions or other positive ions in the base.</span>
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:
last one
they can contain mercury that is Very harmful to humans