Answer:
The voltage is ![E = 0.268V](https://tex.z-dn.net/?f=E%20%3D%200.268V)
Explanation:
Since the main source of
is the sea water then
The equation for the reaction
in sea water would be
![Cl^- ----->\frac{1}{2}Cl_2 + e^-](https://tex.z-dn.net/?f=Cl%5E-%20-----%3E%5Cfrac%7B1%7D%7B2%7DCl_2%20%2B%20e%5E-)
that is the ion would form a molecule
and then release an electron
For river water
![\frac{1}{2}Cl_2 + e^- -----> Cl^-](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7DCl_2%20%2B%20e%5E-%20-----%3E%20Cl%5E-)
I.e the molecule would gain an electron and forms an ion
Now
acts as reactant for seawater reaction and product for river water
The voltage of the concentration cell at initial stage is ![E_0 = 0](https://tex.z-dn.net/?f=E_0%20%3D%200)
Now at the voltage for the cell with
concentration difference between sea water and river water is mathematical denoted as
![E = E_0 - \frac{0.059}{n_e} log\frac{[Cl^-]_{product}}{[Cl^-]_{reactant}}](https://tex.z-dn.net/?f=E%20%3D%20E_0%20-%20%5Cfrac%7B0.059%7D%7Bn_e%7D%20log%5Cfrac%7B%5BCl%5E-%5D_%7Bproduct%7D%7D%7B%5BCl%5E-%5D_%7Breactant%7D%7D)
Where
is the number of electron = 1
So substituting values we have
![E = 0 - \frac{0.059}{1} log\frac{1.0*10^{-3}}{35}](https://tex.z-dn.net/?f=E%20%3D%200%20-%20%5Cfrac%7B0.059%7D%7B1%7D%20log%5Cfrac%7B1.0%2A10%5E%7B-3%7D%7D%7B35%7D)
Removing the negative sign
![E = \frac{0.059}{1} log\frac{35}{1.0*10^{-3}}](https://tex.z-dn.net/?f=E%20%3D%20%5Cfrac%7B0.059%7D%7B1%7D%20log%5Cfrac%7B35%7D%7B1.0%2A10%5E%7B-3%7D%7D)
![E = 0.268V](https://tex.z-dn.net/?f=E%20%3D%200.268V)
Here we have to get the moles of water generated by the combustion of vitamin C.
4 moles of water (H₂O) will generate from the combustion of vitamin C.
The vitamin C is the ascorbic acid having the molecular formula C₆H₈O₆. On decomposition it produces water (H₂O) and carbon di oxide (CO₂).
The molecular weight of ascorbic acid is 176.12 g/mole.
In this analysis 0.163g of H₂O produces from 0.400g of vitamin C.
Thus from 176.12 g of vitamin C
×176.12 = 71.768 g of H₂O will produce.
The molecular weight of H₂O is 18 g/mole. Thus 71.768 g is equivalent to
= 3.98 ≅ 4
Thus 1 mole of vitamin C (ascorbic acid) produces 4 moles of water on combustion.
The balanced combustion [in presence of excess oxygen (O₂)] reaction can be written as- C₆H₈O₆ + 5O₂ = 4H₂O + 6CO₂.
Thus the moles of water generated from combustion of vitamin C is determined.
Answer:
Saffi only
Explanation:
I just took the test and that was the correct answer :)