Explanation:
Non-spontaneous reactions take place in electrolytic cells using an external power supply.
The positive electrode is the anode where oxidation takes place.
The aqueous metal ion (Mx^+) is reduced at the cathode to produce the solid metal.

Explanation:​

Metals and acids react to produce a salt and hydrogen gas. The formulae of the ions are Mg2+ and NO3−, therefore for a neutral salt, two nitrate ions are required for each magnesium ion.

Explanation:​
A tenfold decrease in [H+], leads to a $\mathrm{pH}$ increase of 1.

Explanation​:
Metal oxides produce basic solutions when dissolved in water. Non-metal oxides produce acidic solutions when dissolved in water.
Silicon dioxide does not react with water, but reacts with concentrated alkalis to form silicates: SiO2(s)+2 OH−(aq)→SiO32−(aq)+H2O(l)

Explanation​:
Cathode site of reduction, anode site of oxidation, use CROA to remember this.
Reduction is the gain of electrons.

Explanation​:
In electrolysis the positive electrode is the anode. Oxidation takes place at the anode.

Explanation:​
A base accepts a hydrogen ion, whereas an acid donates it. The base in the forward and backward reactions are therefore the species which gain hydrogen ions during the reaction: NH3 and HSO4^−, respectively.
This question is moderately difficult as the student must recall the definition of a base and identify specific examples of bases in a reaction equation.

Explanation​:
By definition, strong acids completely dissociate in water.

Explanation:​
Students must compare ways of breaking bonds. They must recall that homolytic fissions form free radicals (species with unpaired electrons) as shared electrons split once the bond breaks.
In contrast, heterolytic fissions produce positively and negatively charged particles (ions) as both shared electrons go to just one of the atoms in the bond.

This question is categorized as hard. Students must recall the ways of breaking bonds, distinguish homolytic and heterolytic fission, and understand that free radicals have unpaired electrons.

Neutralization involves acid and base reacting to form a salt and water. Reaction A does not show those criteria to be categorized as a neutralization reaction.

Explanation​:
Mg(s) loses electrons to produce $).$ Loss of electrons is oxidation which takes place at the anode.

Explanation:​
Water accepts a hydrogen ion to produce H3O^+. This question is easy as the formation of H3O^+ is covered explicitly in the syllabus

Explanation:​
Assuming "x" to be the oxidation number of N:

• In nitrate NO3− , x +3 (-2) = -1. Therefore, x = +5
• In nitrite NO2− , x +2 (-2) = -1. Therefore, x = +3

Explanation:​
A heterolytic fission involves the break up of a bond so that both electrons go to one of the atoms. This process produces ions, as shown below.

The heterolytic fission requested occurs like this:

The species produced are ions, (CH3)3C^+ and Br^−.

This question is categorized as hard. The student must interpret the condensed formula given, recall how heterolytic fissions occur in that specific bond, and predict the product of this process.

Explanation:​
The HPO^4− ion contains two negatively charged oxygen atoms which can bond to hydrogen ions, producing phosphoric acid (H3PO^4​).
The HPO^4− ion can therefore react with two H+ ions.
This question is moderately difficult as the student must recognise that H^+ ions bond to the negatively charged oxygen atoms, or that HPO^4− is derived from H3PO^4​.

Explanation​:
The positive ions (cations) move in the direction of the cathode as the positive Cu2+ ions are used up.
Zn being more reactive than copper, Zn(s) is the anode where oxidation occurs, and Cu(s) is the cathode where reduction of Cu2+(aq) occur

Explanation​:
Zn2+(l) gains electrons and is reduced to Zn(s) at the cathode. Cl−(l) loses electrons and is oxidised to Cl2(g) at the anode.

Explanation:​
Least reactive metal is the strongest oxidizing agent/ weakest reducing agent.
Z is the most reactive metal (can displace both X and Y), followed by Y(can only displace X), and lastly, X (cannot displace any).

Explanation:
In a primary alcohol, the OH group is bonded to a CH2 group. The alcohol group initially reacts with KMnO4​ to form an aldehyde (CHO) group, as in option B.
However, the aldehyde is further oxidzed to a carboxylic acid (COOH) group unless it is removed by distillation. Here, the solution is heated under reflux, so the carboxylic acid is the major product.

Explanation:
NaOH is a strong base and has a high pH,  NH3,​ is a weak base with a lower $\mathrm{pH}$ than NaOH. CH3COOH​ is a weak acid, $\mathrm{HCl}$ is a strong acid and so has the lowest pH.

Explanation:​
In equation 1, the oxidation state of Cl decreases from +5 to 0 (reduced), and the oxidation state of Iodine increases from 0 to +5 ( oxidized).
In equation 2, the oxidation state of Cl increases from 0 to +1 in NaClO (oxidized), and also decreases from 0 to -1 in NaCl (reduced).

Explanation:​
$\mathrm{pH}$ = $-$.
For concentrations of H+ greater than 1 mol dm^−3, this would result in a negative $\mathrm{pH}$ value.

Explanation:​
Spontaneous reactions occur in voltaic cells converting chemical energy to electrical energy, whereas, non-spontaneous reactions occur in electrolytic cells requiring electrical energy and converting this to chemical energy.
Electrolytic cells typically consist of one reaction vessel containing the aqueous of molten electrolyte. No salt bridge is therefore required.