A student measures the temperature change when different masses of anhydrous calcium chloride are added to 50 cm350\ \text{cm}^350 cm3 of water. She records the initial temperature of the water before adding the solid.
The diagrams of the thermometer show the highest temperature reached, in ∘C^\circ\text{C}∘C, for each experiment.
Use the diagrams and the initial temperatures provided to complete the table of results:
| Mass of anhydrous calcium chloride in g\text{g}g | Initial temperature in ∘C^\circ\text{C}∘C | Highest temperature reached in ∘C^\circ\text{C}∘C | Increase in temperature in ∘C^\circ\text{C}∘C |
|---|---|---|---|
| 2.0 | 20.0 | ||
| 4.0 | 20.0 | ||
| 6.0 | 19.0 | ||
| 8.0 | 19.0 |
Another student repeats the experiment. The table shows their results:
| Mass of anhydrous calcium chloride in g\text{g}g | 2.0 | 4.0 | 6.0 | 8.0 | 10.0 |
|---|---|---|---|---|---|
| Increase in temperature in ∘C^\circ\text{C}∘C | 5.5 | 11.0 | 16.5 | 16.5 | 16.5 |
Plot this student's results on the grid below. Draw a straight line of best fit through the first three points and another straight line of best fit through the last three points. Make sure the two lines cross.
Use your graph to find the mass of anhydrous calcium chloride required to produce an increase in temperature of 13.2 ∘C13.2\ ^\circ\text{C}13.2 ∘C.
