A student measures the temperature change when different masses of anhydrous calcium chloride dissolve in 50 cm3 of water. The results are shown. mass of CaCl2 / g : 2.0, 4.0, 6.0, 8.0, 10.0 temperature change / degC : 3.0, 6.0, 9.0, 12.0, 15.0 The student is given graph paper with mass on the x-axis (already labelled 0 to 10 g) and a blank y-axis.