A-Level H2 Chemistry

Question 1

What is the electronic configuration of a ground-state iron atom (Fe, Z=26)?

Accepted Answer

[Ar] 3d⁶ 4s²

Answer

[Ar] 3d⁸

Answer

[Ar] 4s² 4p⁶

Answer

[Ne] 3d⁶ 4s²

Question 2

What is the enthalpy change of neutralisation and what is its typical value for a strong acid–strong base reaction?

Accepted Answer

−56 kJ/mol

Answer

−46 kJ/mol

Answer

+56 kJ/mol

Answer

−100 kJ/mol

Question 3

Which hybridisation is exhibited by the carbon atoms in benzene?

Accepted Answer

sp²

Answer

sp³

Answer

sp

Answer

sp³d

Question 4

What is the meaning of 'rate of reaction'?

Accepted Answer

Change in concentration of a reactant or product per unit time

Answer

Total moles of product formed

Answer

Activation energy of the reaction

Answer

Total energy released

Question 5

What is the order of reaction if doubling the concentration of A doubles the rate?

Accepted Answer

First order

Answer

Zero order

Answer

Second order

Answer

Third order

Question 6

In the Born-Haber cycle, which step represents the formation of gaseous ions from gaseous atoms?

Accepted Answer

Ionisation energy

Answer

Enthalpy of atomisation

Answer

Lattice enthalpy

Answer

Electron affinity