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

Explanation:​
A secondary alcohol is a compound in which the carbon attached to the hydroxyl group is also attached to two other carbons.
Upon its oxidation, a removal of 2H atoms occurs and a ketone is formed.

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

Explanation​:
Step 1 is a free radical substitution, converting the alkane to a chloroalkane and producing HCl as a by-product.
Step 2 is a nucleophilic substitution, in which the C−Cl bond breaks and is replaced by a hydroxyl (C−OH) group; the products are an alcohol and sodium chloride.
Step 3 is an oxidation. To prevent the aldehyde from being oxidised further to a carboxylic acid, the product must be removed by distillation as it forms.

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:​
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:
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​:
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:​
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:​
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:​
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.

Explanation:
Use the mnemonic CNAP; cathode negative, anode positive for the polarity in electrolytic cells.

Explanation:​

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

A

Explanation:​
NaOH is a base so reacts with a hydrogen ion. HNO3​, nitric acid, releases a hydrogen ion through the breaking (heterolysis) of the O-H bond.
This question is moderately difficult as the student must recognise that NaOH is a base and HNO3​ an acid and correctly interpret a structural formula that may be unfamiliar.

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:​
Oxidation state of Mn in MnO4^− is +7. The change in oxidation state is from +3 to +7.
Oxidation refers to an increase in oxidation state.

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

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:​
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.