# 25 August Science 8 Finding the density of liquids; Saturated solutions and their densities

Follow the method described in class for determining the density of liquids. Follow directions for gathering materials, keeping substances from becoming contaminated, keeping glassware clean and in tact.

1. Need to measure the mass of an empty and dry cylinder.
2. Need to measure some volume of a liquid. Why not use 100 ml or cm3
to make the arithmetic easier.
3. Need to find the mass of the cylinder and the 100 ml or cm3 sample of the liquid.
4. The density is found by dividing the mass by the volume. Density is then reported as the mass of 1 unit of volume–in this case grams / ml or grams/cm3    (g/cm3  ).
5. Enter your results in the spreadsheet (1 sheet for each substance): <https://docs.google.com/a/aes.ac.in/spreadsheets/d/1akCEeG7ARiZtiFkPaWL3SdewOI0vYHVNHvGVIeydZ84/edit?usp=sharing>. You will need to let Dr. F know when you are ready so he can give you editing privileges.

If there is time, we will begin making saturated solutions of table salt and white sugar. Use 100 ml of heated water from the kettle. Take the temperature at the time you get the water. (It will cool while you dissolve the substances.) Keep track of how much salt you add to the 100 ml of water. Add until no more dissolves. Try not to add to much excess. When no more dissolves, the solution is saturated. When you feel the solution is saturated, find the density of  a 50 ml sample. Do not let any of the undissolved substance get into the cylinder. Enter data: https://docs.google.com/a/aes.ac.in/spreadsheets/d/1jTcyipK0fb_lzh-0ekJixNblGBHENb3bXqVK9r-QWZs/edit?usp=sharing

Pour a little of your saturated salt solution in a petri dish labeled with your names, period, date and time. Set it on the counter top at the back of the room.

Take pictures.