Chemistry Year 12 Random Retrieval

This quiz contains all the questions in the year 12 chemistry section. The website will pick 10 questions at random.

1 / 10

Which of these alkenes will produce the largest %yield of 2-bromopentane when it is reacted with hydrogen bromide?

CH₃CH₂CH₂CH=CH₂

CH₂=CHCH₂CH₃

CH₃CH₂CH=CHCH₃

2 / 10

Why is ethanol a liquid while propane is a gas? (Relative atomic masses: C = 12, H = 1, O = 16)

The molar mass of ethanol is higher than the molar mass of propane

There are more hydrogen atoms in propane than in ethanol

There is hydrogen bonding in ethanol but not in propane

Ethanol is soluble in water while propane is insoluble

3 / 10

Which of these true statements help to explain why the values of the first ionisation enthalpies (energies) of the group 1 metals fall down the group from lithium to caesium?

(i) Down the group, the outer electron gets further from the nucleus

(ii) The charge on the nucleus increases down the group

(iii) Greater shielding means that the attraction between the nucleus and the outer electron reduces down the group

(iv) In all the atoms the outer electron is an s-electron

(i), (ii) and (iii)

(i) and (iii) only

(ii) and (iv) only

(iv) alone

4 / 10

What is the oxidation number of OXYGEN in hydrogen peroxide

H₂O₂

5 / 10

The carbonates of group 2 metals (M):

(i) have the formula of the form MCO₃

(ii) are insoluble in water

(iii) become more difficult to decompose on heating down the group

(iv) decompose on heating to the metal and carbon dioxide

(i), (ii) and (iii)

(i) and (iii) only

(ii) and (iv) only

(iv) alone

6 / 10

Which of these properties of magnesium are also properties of beryllium?

(i) It forms a basic oxide

(ii) It forms an ionic chloride

(iii) It reacts with dilute hydrochloric acid

(iv) It forms a stable oxide with the formula MO (where M represents the metal atom)

(i), (ii) and (iii)

(i) and (iii) only

(ii) and (iv) only

(iv) alone

7 / 10

An example of an endothermic change is the:

reaction of methane with oxygen

melting of ice

condensation of steam

neutralisation of ammonia with hydrochloric acid

8 / 10

The value that you obtain for the enthalpy of combustion Δ_cH of liquid ethanol using mean bond enthalpies is different from the value obtained experimentally, or by using enthalpy of formation Δ_fH of liquid ethanol.

What is the most significant reason for this?

Obtaining the value by experiment allows one to repeat the experiment and take an average.

Mean bond enthalpies can't be used directly to estimate this enthalpy change because ethanol and water are in the liquid state.

Obtaining the value by repeating the experiment allows one to spot anomalous values and then remove them from the calculation of the average.

Use of enthalpies of formation lead to more reliable answers. This is because they have been repeated far more times and the experiments have shown the values to be highly repeatable.

9 / 10

In which of these elements are the atoms or molecules closely packed but free to move around sliding past each other at room temperature?

(i) mercury

(ii) argon

(iii) bromine

(iv) iodine

(i), (ii) and (iii)

(i) and (iii) only

(ii) and (iv) only

(iv) alone

10 / 10

Hydrogen is oxidised when it reacts with:

(i) oxygen to form water

(ii) nitrogen to form ammonia

(iii) chlorine to form hydrogen chloride

(iv) sodium to form sodium hydride

(i), (ii) and (iii)

(i) and (iii) only

(ii) and (iv) only

(iv) alone

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