18 This question is about sodium hydroxide.

(a) (i) Write an ionic equation for the neutralisation reaction between
aqueous sodium hydroxide and hydrochloric acid.
State symbols are not required.
(1)

(ii) State what is meant by standard enthalpy change of neutralisation, \(\Delta_{\text {neut }} H^{\ominus}\).
(2)
................................................................................................................................................................................................................................................................................
................................................................................................................................................................................................................................................................................
................................................................................................................................................................................................................................................................................
................................................................................................................................................................................................................................................................................

(b) A student carried out an investigation to determine the enthalpy change of neutralisation of aqueous sodium hydroxide by hydrochloric acid.
Method
- separate \(25.0 \mathrm{~cm}^{3}\) samples of \(0.80 \mathrm{~mol} \mathrm{dm}^{-3}\) sodium hydroxide and
\(0.80 \mathrm{~mol} \mathrm{dm}^{-3}\) hydrochloric acid were left to reach room temperature
- after two minutes, the solutions were mixed in a copper calorimeter and the temperature was noted at \(30 \mathrm{~s}\) intervals.

(i) Use the graph shown to determine the maximum temperature change, \(\Delta T\), in this experiment. You must show your working on the graph.
(2)
\(\Delta T\). .......................................................... ..

(ii) Calculate the enthalpy change of neutralisation using your answers to (a) and (b)(i). Give a sign and units with your answer.
Assume: no energy is used to heat the container.
the specific heat capacity of the solution \(=4.2 \mathrm{~J}^{\circ} \mathrm{C}^{-1} \mathrm{~g}^{-1}\).
the densities of the solutions of \(\mathrm{NaOH}\) and \(\mathrm{HCl}\) are \(1.0 \mathrm{~g} \mathrm{~cm}^{-3}\).
(3)

(iii) Explain how, if at all, the enthalpy change of neutralisation obtained in
(b)(ii) would differ if the heat capacity of the calorimeter was included
in the calculation.
(2)
................................................................................................................................................................................................................................................................................
................................................................................................................................................................................................................................................................................
................................................................................................................................................................................................................................................................................
................................................................................................................................................................................................................................................................................
................................................................................................................................................................................................................................................................................
................................................................................................................................................................................................................................................................................

(c) Aqueous sodium hydroxide reacts with 1-bromopropane to produce propan-1-ol.

(i) State the type and mechanism of this reaction.
(1)
................................................................................................................................................................................................................................................................................

(ii) Complete the mechanism for this reaction.
Include curly arrows, and relevant lone pairs and dipoles.
(3)

(iii) Under different conditions, sodium hydroxide reacts with 1-bromopropane to form propene.
Name the type of reaction and a suitable solvent.
(2)
Type of reaction
................................................................................................................................................................................................................................................................................
Suitable solvent
................................................................................................................................................................................................................................................................................

This question is about sodium hydroxide. Write an ionic equation for the neutralisation reaction between aqueous sodium hydroxide and hydrochloric acid. State symbols are not required. (1)

Answer:

Knowledge points:

Solution:

Related Question