EVIDENCE OF CHEMICAL REACTION

LABTuesday, September 25th

Pre-Lab Notes

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

Temperature 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

Procedure:

Station One:1. Pour 20ml of diluted grape juice into a glass beaker2. Add 20ml of ammonia to the grape juice 3. Put thermometer into solution mixture4. Observe and record data & observations5. 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 beaker2. Add 25ml of water3. Put thermometer into solution mixture4. Observe and record data & observations

Procedure

Station Three:1. Put 1 scoop of sodium bicarbonate (baking soda)

into glass beaker2. Add 20ml of vinegar3. Put in thermometer in solution mixture4. Observe and record data & observations

Station Four:1. Add 1 scoop of calcium chloride to beaker2. Add 20ml of water3. Put in thermometer into solution mixture4. Observe and record data & observations

Data To Record

Start time Beginning and ending temperatures Things you see, hear, or smell Anything else that you even THINK may

be important (you never know…)

Lab Cleanliness

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!

CER Demo

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)