Explanation:​
H2O is more readily oxidized than Cl^− and SO4^2−, however, when concentrated aqueous NaCl is used, chlorine is produced at the anode

Explanation​:
NH3​ has a non-bonding pair of electrons it can donate to a central metal ion. BH3​ and CH4 do not have non-bonding electrons.

Explanation​:
Statement II is incorrect as acids produce solutions with $\mathrm{pH}$ lower than 7.

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

Explanation​:
$\mathrm{l}$ is a neutral salt, Na2CO3 is a basic salt, and NaOH is a strong base.

Explanation​:
Recall of the nitration intermediate covered in the syllabus. This is formed after the NO2^+ electrophile has been attacked by benzene’s pi electrons.

Explanation​:
By definition an acid is a proton donor. Weak acids only partially dissociate in aqueous solution leading to poor conductivity.

Explanation​:
$)$ gains electrons and is reduced to $\mathrm{Zn}(\mathrm{s})$ at the cathode. $\mathrm{l})$ loses electrons and is oxidised to Cl2(g) at the anode

Explanation:​
ΔGθ = $-$.
For spontaneous reactions, ΔGθ is negative, therefore Ecellθ​ must be positive.

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:​
The HPO4^− ion contains two negatively charged oxygen atoms which can bond to hydrogen ions, producing phosphoric acid (H3PO4​).
The HPO4^− 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 HPO4^− is derived from H3PO4​.

Explanation:​

Metals and acids react to produce a salt and hydrogen gas. The formulae of the ions are Mg^2+ and NO3^−, therefore for a neutral salt, two nitrate ions are required for each magnesium ion.

Explanation​:
Acidic solutions have high H^+ concentrations. Bases have a high concentration of OH^− ions

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.

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

Explanation​:
An acidic buffer solution contains a weak acid and the salt of its conjugate base.