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.
1 proton, 1 electron, and 2 neutrons
The answer is 39.948 g/mol so rounded to the nearest ones would be 40.00 g/mol.
Answer:
Gravity
Explanation:
All matter exerts a force, which is called , that pulls all other matter towards its center. The strength of the force depends on the mass of the object: the Sun has more gravity than Earth, which in turn has more gravity than an apple. Also, the force weakens with distance. Objects far from the Sun won’t be influenced by its gravity.
Answer:
CH4 + 2O2 -> CO2 + 2H2O
Explanation:
This reaction involves the combustion of methane (CH4)
General form of balancing reactions involving combustion of hydrocarbons is
CxHy + [x+(y/4)]O2 -> xCO2 + (y/2)H2O
x= the number of carbon atoms in the compound = 1
y= the number of hydrogen atoms in the compound = 4
CH4 + [(1+(4/4)]O2 -> CO2 + (4/2)H20
CH4 + (1+1)O2 -> CO2 + 2H2O
CH4 + 2O2 -> CO2 + 2H2O
