Question

table 1.1: data on measuring the freezing - point.
concentration of sodium chloride in solution/mol dm^-3\tfreezing point of solution / celsius
0.5\t-1.86
1.0\t-3.72
1.5\t-5.58
2.0\t-7.44

a) construct a graph of concentration of sodium chloride in solution (x - axis) against freezing point of solution (y - axis).
i) create a scale for each axis based on your data. your scale should be large enough that your graph takes up more than half of the available space both vertically and horizontally.
ii) as your temperatures will be below 0°c, your x - axis should be at the top rather than along the bottom, so the y - axis can better represent the negative numbers.
iii) remember to use a ruler to create straight lines that will connect your carefully plotted data points.

b) describe the change in the freezing point of the solution as the concentration of sodium chloride increased.

Explanation:

Step1: Analyze the data trend

As the concentration of sodium - chloride increases from 0.5 mol/dm³ to 2.0 mol/dm³, the freezing point of the solution changes from - 1.86°C to - 7.44°C.

Step2: Describe the change

The freezing point of the solution decreases as the concentration of sodium chloride increases.

Answer:

The freezing point of the solution decreases as the concentration of sodium chloride increases.