Answer:
Explanation:
Cu²⁺ + 2e⁻ → Cu ( copper gets reduced )
Cu → Cu²⁺ + 2e⁻ ( copper gets oxidized )
Oxidation:
Oxidation involve the removal of electrons and oxidation state of atom of an element is increased.
Reduction:
Reduction involve the gain of electron and oxidation number is decreased.
Consider the following reactions.
4KI + 2CuCl₂ → 2CuI + I₂ + 4KCl
the oxidation state of copper is changed from +2 to +1 so copper get reduced.
CO + H₂O → CO₂ + H₂
the oxidation state of carbon is +2 on reactant side and on product side it becomes +4 so carbon get oxidized.
Na₂CO₃ + H₃PO₄ → Na₂HPO₄ + CO₂ + H₂O
The oxidation state of carbon on reactant side is +4. while on product side is also +4 so it neither oxidized nor reduced.
H₂S + 2NaOH → Na₂S + 2H₂O
The oxidation sate of sulfur is -2 on reactant side and in product side it is also -2 so it neither oxidized nor reduced.
Answer:
The following reaction will occur at cathode:

Explanation:
The two half reaction during electrolysis of aqueous nickel sulfate will be
a) anode reaction :
Water will undergo oxidation and will evolve oxygen gas at anode as shown in the given reaction:

b) Cathode reaction: The reduction of Nickel ion will occur by gain of two electrons as shown in the given equation:

Thus the overall reaction will be:

Answer:
C.
Explanation:
Since they're changing from a gas to a liquid, the particles are getting squished together more if that makes sense. They're not vibrating that fast anymore when they're in liquid form.
Answer: No
Explanation:
A periodic table can be defined as the table in which the row of chemical elements are present. All the elements of the row have same number of electron shells.
The arrangement of elements is based on atomic numbers, electron shell model and other chemical properties. The elements are placed in increasing order of atomic number.
This table does not give information about the occurrence of the elements.