Answer:
D. Ni²⁺
Explanation:
We know at once that the answer cannot be A or C, because Ni and Cu are already in their lowest oxidation states.
The correct answer must be either B or D.
An electrolytic cell is the opposite of a galvanic cell. In the former, the reaction proceeds spontaneously. In the latter, you must force the reaction to occur.
One strategy to solve this problem is:
- Look up the standard reduction potentials for the half reaction·
- Figure out the spontaneous direction.
- Write the equation in the reverse direction.
1. Standard reduction potentials
E°/V
Cu²⁺ + 2e⁻ ⟶ Cu; 0.3419
Ni²⁺ + 2e⁻ ⟶ Ni; -0.257
2. Galvanic Cell
We reverse the direction of the more negative half cell and add.
<u>E°/V
</u>
Ni ⟶ Ni²⁺ + 2e⁻; 0.257
<u>Cu²⁺ + 2e⁻ ⟶ Cu; </u> 0.3419
Ni + Cu²⁺ ⟶ Cu + Ni²⁺; 0.599
This is the spontaneous direction.
Cu²⁺ is reduced to Cu.
3. Electrochemical cell
<u>E°/V</u>
Ni²⁺ + 2e⁻ ⟶ Ni; -0.257
<u>Cu ⟶ Cu²⁺ + 2e⁻; </u> <u>-0.3419</u>
Cu + Ni²⁺ ⟶ Ni + Cu²⁺; -0.599
This is the non-spontaneous direction.
Ni²⁺ is reduced to Ni in the electrolytic cell.
A. Cs - 55 electrons, 55 protons, 77 neutrons
B. Co - 27 electrons, 22 protons, 32 neutrons
C. Tm - 69 electrons, 69 protons, 94 neutrons
D. Zn - 30 electrons, 30 protons, 40 neutrons
For any neutral atom, protons = electrons = atomic number. Neutrons = atomic mass - atomic number.
Iodine is going to form anions capturing electrons from some other element more electropositive
Answer:
They all can, but HCl would be the strongest conductors because they are strong acids/bases, meaning their ions dissociate at a faster rate in aqueous solution.
The
balanced reaction would be written as:
<span>
C7H6O3 + C4H6O3--->C9H8O4 + HC2H3O2
To determine the percent yield, we need to first
determine the theoretical yield if the reaction were to proceed completely.
Then, we divide the actual yield that is given to the theoretical yield times
100 percent. The limiting reactant from the reaction would be salicylic acid.
We do as follows:
<span>Theoretical yield: 50.05 g C7H6O3 ( 1 mol /
138.21 g ) ( 1 mol C9H8O4 / 1 mol C7H6O3 ) ( 180.157 g / mol ) = 65.24 g C9H8O4 should be produced
Percent yield = 55.45 / 65.24 x 100 = 84.99%
<span>
Therefore, the percent yield for the given amount of salicylic acid is 84.99%
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