13 Solder is a mixture of lead and tin - OCR Gateway - GCSE Chemistry: Combined Science - Question 13 - 2021 - Paper 9

To plot the data, follow these steps:

1. Identify the Data: Based on the provided table, the relevant pairs of percentage of tin in solder and their corresponding melting points are:

   • (0, 320)
   • (20, 280)
   • (40, 240)
   • (80, 220)
   • (90, 230)
   • (100, 240)

2. Setup the Grid: Make sure that the grid in Fig. 13.2 has the x-axis labeled as 'Percentage of tin in solder (%)' ranging from 0 to 100, and the y-axis labeled as 'Melting point (°C)' ranging from 150 to 350.

3. Plot Each Point: Carefully plot each point on the grid as follows:

   • For (0, 320), plot a point at x = 0 and y = 320.
   • For (20, 280), plot a point at x = 20 and y = 280.
   • For (40, 240), plot a point at x = 40 and y = 240.
   • For (80, 220), plot a point at x = 80 and y = 220.
   • For (90, 230), plot a point at x = 90 and y = 230.
   • For (100, 240), plot a point at x = 100 and y = 240.

4. Draw the Line of Best Fit: Once all points are plotted, draw a straight line (or curve) that best represents the trend of the plotted points. The line should not extrapolate beyond the plotted points.

5. Check Points: Ensure that your points are accurately placed and that the line does not extend outside the given range, as this affects the validity of the plotted data.