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

Explanation​:
Statement II is incorrect as acids produce solutions with pH lower than 7.

Explanation​:
NaOH is a strong base and so would release a high concentration of OH^− ions in water. Choices A and C are incorrect as HCl and H2SO4 are strong acids and would give low $\mathrm{pH}$s. $\mathrm{NaCl}$ is a neutral salt.

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:
H2SO4 is a strong acid and fully ionizes its first proton leading to a high H+ concentration.
HSO4− is a weak acid that only partially dissociates to produce $.$ [SO42−] is, therefore, low and not equal to HSO4−

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

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

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:​

Acids react with carbonates to produce a salt, water, and carbon dioxide.

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:​
Kc>1, and so lies towards the right with the yellow product at equilibrium; the color would therefore be a pale green due to more yellow than blue.
When an acid is added, it reacts with the OH−reducing its concentration. Equilibrium shifts to the right to oppose that change.

Kc only changes with temperature. Adding an alkali would increase the OH− concentration and therefore the equilibrium would shift to the left to oppose that change. Kc​ again would remain the same as it is only affected by temperature.

Explanation:​

Hydrochloric acid produces chloride salts, nitric acid produces nitrate (NO3^−​) salts, sulphuric acid produces sulphate (SO4^2−​) salts, and ethanoic acid produces ethanoate (CH3​COO^−) salts.

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​:
In this nucleophilic substitution reaction, the hydroxide donates a lone pair to break the C-Br bond and form a new C-O bond. The C atom of compound B accepts the electron pair, so is an electrophile.
The compound is a secondary bromoalkane, as the C atom of the C-Br bond is attached to two C atoms.

Explanation:​
Reducing agent is a substance that is oxidized.
Oxidation state of Zn increases from 0 to +2, whereas the oxidation state of N decreases from +5 to +4.
The oxidation state of H remains +1.
The oxidation state of O remains -2.

Explanation:​
A nucleophile is a species that is electron-rich and an electron donor. An electrophile is an electron deficient species.

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

Explanation:​
C3H8​ is a saturated alkane and C3H6​ is an unsaturated alkene. The test of unsaturation using Br2(aq) can demonstrate the presence or absence of a carbon-carbon double bond.
In the presence of a double bond, Br2(aq) can add across the double bond in the alkene producing a dibromo-alkane, and a change of color from brown to colorless will be observed.
In the case of the absence of a double bond (saturated hydrocarbon), no color change would occur.

Explanation:​
A conjugate acid-base pair differ by a single hydrogen ion. Carbonic acid and carbonate (choice A) differ by two hydrogen ions so are not a conjugate acid-base pair. Boric acid and its hydroxide adduct (choice B) differ by a hydroxide ion and ammonia and hydroxylamine (choice D) by an oxygen atom.
This question is categorised as very hard as the student must recall the definition of a conjugate acid-base pair, interpret the structural formulas of unfamiliar molecules and identify a conjugate acid and base without the aid of a reaction equation.

Explanation​:
By definition, the more readily an acid releases a proton, the less likely the conjugate base is to accept a proton.

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:​
The conjugate base of HCl is the compound produced when a hydrogen ion is removed. The conjugate base is therefore the chloride ion, Cl^−.
This question is hard as the student must link the names of chemicals to their formula and identify a conjugate base without the aid of an explicit reaction equation.