Lab 8 The Density of Water Purpose Background PART 1 Compare the density of tap water to distilled water. Background Tap water contains various amounts of dissolved ions and minerals. Distilled water is pure water (H2O)

10.0 mL pipet, distilled water, 10.0 mL graduated cylinder, tap water, Experiment PART 1 Take all measurements necessary to calculate the density of water in g/ml **WRITE DOWN all of those measurements here. Make sure to measure ACCURATELY. Materials: 10.0 mL pipet, distilled water, 10.0 mL graduated cylinder, tap water, digital scale

Calculate the density of pure water in g/ml All calculations must be rounded to the correct number of significant figures. SHOW ALL OF YOUR WORK. Analysis Calculate the density of pure water in g/ml 2. Calculate the density of tap water in g/ml Results The results statement should be a statement that compares the densities of tap and distilled water. Include quantitative data and any information from the background information to justify your answer.

How does a change in volume affect the density of distilled water? PART 2 Questions How does a change in volume affect the density of distilled water? Hypothesis ____________________________________________________________________________________________________________

**Fill in the following data table. Make sure to measure ACCURATELY. Experiment PART 2 Take all measurements necessary to calculate the density of water in g/ml **Fill in the following data table. Make sure to measure ACCURATELY. Materials: 10.0 ml pipet, distilled water 50 ml graduated cylinder, digital scale

All calculations must be rounded to the correct number of significant figures. Remember your labels! Analysis Volume of Distilled Water (ml) Mass of water (g) Density of Water 10.0 ml 20.0 ml 30.0 ml 40.0 ml 50.0 ml CALCULATE AVERAGE

If you were going to graph the data from Part 2, Analysis (con’t) 1. According to the CRC Handbook of Chemistry and Physics, the density of pure water is pure water is 0.99823 g/ml. Using the AVERAGE from your data table above, calculate your : a) error b) percent error. If you were going to graph the data from Part 2, which graph (from the right) would it look like? Why? Conclusion: Remember to include all 3 parts!

1. Name some sources of error in this experiment. Questions 1. Name some sources of error in this experiment. 2. You measured 10.0 mL of water at room temperature. What would happen to this volume if the temperature increased? 3. What happens to the density of water as the temperature of the water increases? 4. How was density affected by using 10.0 ml of water as compared to using 50.0 ml? 5. Is density an intensive or extensive property of water? Use data from this lab to justify your answer.