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Edexcel A-Level Chemistry Graph Skills

Practise Edexcel A-Level Chemistry graph skills through plotted kinetics and calibration graphs, best-fit lines, gradient work and graphical readings.

Syllabus
Pearson Edexcel International Advanced Subsidiary/Advanced Level
Course
Chemistry XCH11/YCH11
Level
AS

Exam points

  • plot chemistry data with labelled axes, units, suitable scales and accurate points
  • draw best-fit lines or curves, including origin lines and anomalous-point decisions
  • read concentrations, gradients or unknown masses from calibration and kinetics graphs

Covered syllabus points

B.3.1—Translating between data formsB.3.2—Plotting two variables

B.3 Graphs question 1

[Maximum number: 4]
Table for Question B.3 Graphs question 1 — Edexcel A-Level Chemistry AS

Question (a)

(a)
Figure for Question (a) — Edexcel A-Level Chemistry AS
[ 2 ]

Question (b)

B.3 Graphs question 2

[Maximum number: 4]

Sodium hydroxide can be obtained as a hydrate, NaOH⋅×H2O\mathrm{NaOH} \cdot \times \mathrm{H}_{2} \mathrm{O}.
When heated, the water of crystallisation is lost, leaving anhydrous sodium hydroxide, NaOH , as shown in the equation.

NaOH⋅xH2O→NaOH+xH2O\mathrm{NaOH} \cdot x \mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{NaOH}+x \mathrm{H}_{2} \mathrm{O}

An experiment was carried out to determine the value of x in NaOH⋅×H2O\mathrm{NaOH} \cdot \times \mathrm{H}_{2} \mathrm{O}.

Procedure

Step 1 Weigh and record the mass of a clean, dry crucible.
Step 2 Add approximately 1.0 g of NaOH⋅×H2O\mathrm{NaOH} \cdot \times \mathrm{H}_{2} \mathrm{O} to the crucible and record the mass.
Step 3 Heat the crucible and its contents until a constant mass has been reached.
Step 4 After allowing to cool, reweigh the crucible and the anhydrous solid.
Step 5 Calculate and record the mass of the anhydrous solid.
Repeat Steps 1 to 5 using a different mass of the hydrated sodium hydroxide.

Results

Table for Question B.3 Graphs question 2 — Edexcel A-Level Chemistry AS

Question (a)

(a)

Complete a graph of the results by
- plotting the points
- labelling the axes
- including a straight line of best fit.

Figure for Question (a) — Edexcel A-Level Chemistry AS
[ 3 ]

Question (b)

(b)

ii) Use your graph to determine the mass of NaOH⋅×H2O\mathrm{NaOH} \cdot \times \mathrm{H}_{2} \mathrm{O} needed to form 4.0 g of NaOH . You must show your working on the graph.

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