Tuesday, September 25th

 Chemical change vs. Physical Change  Physical change = just changes form  Chemical change = something new is made  Evidence of chemical change:  Gas is produced by itself (not boiling bubbles)  Temperature change by itself  Smell change  Color change

 Increases temperature (gets hotter)  Exothermic  Releases heat  This will feel hot to the touch or you will see the temperature go up  Endothermic  Takes in heat  Feels cold to the touch or you will see the temperature go down

 Station One: 1. Pour 20ml of diluted grape juice into a glass beaker 2. Add 20ml of ammonia to the grape juice 3. Put thermometer into solution mixture 4. Observe and record data & observations 5. Pour solution down the drain with copious amounts of water  Station Two: 1. Add 1 scoop of citric acid and 1 scoop of baking soda to the glass beaker 2. Add 25ml of water 3. Put thermometer into solution mixture 4. Observe and record data & observations

 Station Three: 1. Put 1 scoop of sodium bicarbonate (baking soda) into glass beaker 2. Add 20ml of vinegar 3. Put in thermometer in solution mixture 4. Observe and record data & observations  Station Four: 1. Add 1 scoop of calcium chloride to beaker 2. Add 20ml of water 3. Put in thermometer into solution mixture 4. Observe and record data & observations

 Start time  Beginning and ending temperatures  Things you see, hear, or smell  Anything else that you even THINK may be important (you never know…)

 Gently rinse out and dry all glassware  Gently rise off and dry thermometers  Make sure counters are kept dry and clean  Clean up any water that spills on the counter or floor Your class WILL NOT be dismissed if any area is dirty. Help others in keeping the room clean!

With 5 minutes left of class, I will do a demo for you. You must determine if what I did was a physical or chemical change (claim). Observe and record data that happens (evidence). Use your pre-lab notes to explain why it happened (reasoning)