Topic 6 and 7 Revision AS

Which alkane has the highest boiling temperature?

•   hexane

• pentane

• 2-methylpentane

• 2,3-dimethylbutane

Which alkane has the strongest London forces in the liquid phase?

• (CH₃)₄C

• CH₃CH₂CH₂CH₂CH₃

• (C₂H₅)₄C

• CH₃(CH₂)₇CH₃

Which equation represents the standard enthalpy change of atomisation of bromine?

• A

• B

• C

• D

Which sequence shows the molecules in order of increasing boiling temperature?

• H₂O < Br₂ < Cl₂ < CH₄

• Br₂ < CH₄ < Cl₂ < H₂O

• Cl₂ < CH₄ < H₂O < Br₂

• CH₄ < Cl₂ < Br₂ < H₂O

Which row shows the hydrogen halides in order of increasing boiling temperature?

• A

• B

• C

• D

Why is the boiling temperature of hydrogen iodide higher than that of hydrogen bromide?

• hydrogen iodide has stronger London forces than hydrogen bromide

• hydrogen iodide has a larger permanent dipole than hydrogen bromide

• hydrogen iodide has stronger hydrogen bonds than hydrogen bromide

• the H—I bond is stronger than the H—Br bond

Hydrogen reacts with oxygen to form steam.

H₂(g)  +  ¹⁄₂O₂(g)  →  H2O(g)              ΔH = −242 kJ mol⁻¹

What is the bond enthalpy of the O—H bond, in kJ mol⁻¹?

• 221.5

• 463.5

• 588

• 927

The mean C–F bond enthalpy is +485 kJ mol^–1.

Which process has an enthalpy change of +1940 kJ mol^–1?

• A

• B

• C

• D

Use the data shown.

What is the standard enthalpy change of formation of methane (CH₄) in kJ mol^–1?

• −1791

• −75

• +75

• +1791

In an experiment, 50.0 cm³ of 1.0 mol dm⁻³ HCl(aq) reacts with
50.0 cm³ of 1.0 mol dm⁻³ NaOH(aq).

The energy released = 2500 J.

The specific heat capacity of the mixture is 4.18 J g⁻¹ °C⁻¹

What temperature change occurs in the reaction?

• an increase of 6.0°C

• a decrease of 6.0°C

• an increase of 12.0°C

• a decrease of 12.0°C