Name: Ayşe Eda Tarakcı Class: 9/D 218 Partners: Aslıhan Tekinırk Sena Sevindi Specific Heat Capacity of Tap Water Data Performed: March 9, 2012 Introduction: Pure substances have fixed melting and boiling points. If we add a different substance in a pure substance, its melting and boiling points changes. In this experiment, our goal is measuring the temperature of tap water till it boils and then calculating its specific heat capacity by using the formula e = mcΔT which shows what we need to know for this experiment: mass of water and change in temperature. Hypothesis: If the specific heat capacity of pure water is 4000, the specific heat capacity of tap water will be more than 4000 because its impure. List of Equipment That We Used During The Experiment 1) A kettle – to boil water 2) A stopwatch – to control the time during heating and boiling 3) Thermometer – to measure the temperature of tap water during the whole experiment 1 Procedure: Before we started boiling the water, we measured its initial temperature and its mass which was 0.5 liter. After writing down the values, we turned on the kettle and checked the time by using a stopwatch until it boiled. When the kettle dried, we looked under it to learn the power of water which was 1000 W. The values that we got from the experiment were going to help us to calculate the specific heat capacity of tap water. With our knowledge that we’ve already known from older classes, the values will be changeable during all of four experiments because of the conditions. The formula that we used during the experiment e = mcΔT which can be also written as energy transferred = mass x specific heat capacity x change in temperature. According to this table, boiling points and times are different, so the experiment has been repeated for three times to find nearest value. According to our formula which is energy transferred = mass x specific heat capacity x change in temperature, we calculated the specific heat capacity of tap water. For the 1st experiment: e = mcΔT 0.5 x c x 76 = e If e = change in time x power of kettle, it’s equal to 210 s x 1000 W. 38 x c = 210000 2 210000/38 = c So c = 5526 For the 2st experiment: e = mcΔT 0.5 x c x 82= 235 x 1000 41 x c = 235000 2350000/41 = c So c = 5731 For the 3st experiment: e = mcΔT 0.5 x c x 82 = 227 x 1000 41 x c = 227000 227000/41 = c So c = 5536 For the 4st experiment: e = mcΔT 0.5 x c x 80 = e 40 x c = 229000 229000/40 = c c = 5725 After finding all of the specific heat capacity values, we calculated the average. (5526 + 5731 + 5736 + 5725) / 4 = 22518 / 4 = 5629,5 (specific heat capacity of tap water) Conclusion: The hypothesis was “If the specific heat capacity of pure water is 4000, the specific heat capacity of tap water will be more than 4000 because of its impurity.” During the experiment, we learned that impure substances have higher specific heat capacities. 3