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:
By definition, these are the standard conditions that must be recalled.

Explanation:
Lewis bases are electron pair donors and so, must have a lone (non-bonding) pair of electrons.

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:
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:
Indicators are weak acids or bases where the components of their conjugate base/acid have different colours.

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

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

Explanation:
The student must identify the reagents and conditions for three reactions. Only information stated explicitly in the syllabus is needed and no interpretation of structural formulas is required. This question is therefore, categorized as “easy”.
Alkenes react with HCl in an addition reaction, alkanes react with halogens in the presence of UV light through free radical substitution, and halogenoalkanes react with NaOH in a nucleophilic substitution reaction.

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:
The student must be sufficiently familiar with the reactions covered in the syllabus to realize that sodium hydroxide would not be useful for producing a diol from an alkene. Alternatively, the question could be answered by recalling the use of sodium hydroxide in the other three reactions. The question is categorized as easy as only limited knowledge of reactions in the literature is needed.
Reactions B and C are both acid-base reactions where NaOH deprotonates the organic species.
Reaction D is a nucleophilic substitution of a halogenoalkane with OH− as the nucleophile.
Reaction A would require first halogenation (with e.g. Br2) followed by nucleophilic substitution.

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:
Weak acids produce strong conjugate bases. The salt when dissolved in solution would therefore be basic.

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

Explanation:
A tenfold decrease in [H+], leads to a pH increase of 1.

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

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