Pg1087 #28-32 p1112 #65,67,68

Solubility

Thursdays worksheet

Going to

I'm going to post the enthalpy tomorrow because I'm still learning the whole thing.....

Calorimetery worksheet

Heat of Combustion of a Candle

Purpose:

  To observe a burning candle and calculate the heat associated with the combustion reaction

Materials:

 Ruler

 Candle

 Aluminum foil

 Balance

 Safety matches

Procedure:

1: Measure and record the length of a candle in centimeters

2: Place the candle on a small piece of aluminum foil and measure the mass of the foil-candle system.

Note the time as you light the candle. Let the candle burn for about 5 minutes. Caution keep clothing away from flame. While you wait begin answering the data and conclusion questions.

3: Extinguish the candle and record the time.

4: Measure the mass of the foil candle system again. Do not try to measure the mass while the candle is burning.

Data

Length before: 5.9cm  Mass before:1.53g

Length After: 3.5 cm    Mass after: 1.16

Analysis and Conclusion

1: (description) the fuse is engulfed in flame as the flame spins gracefully off the top. 

2: Wick

3: The wax holds it up and slows it down.

4: Because the flame puts off heat.

5: Loss .37g and 2.4 cm.   This data the most consistent with the wax burning

6: You light the wick and it ignites and guides the flame from the burning wax.

7: C20H42 + 20 O2= 20 CO2 + 21 H2O

8: .37/283(molar mass)=.0013mol

9: 42 jk/mol

10: .05jk

P 1176 #38,40

P 1189 #66

Heat of Fusion of Ice-Lab

Purpose: The purpose of this experiment is to find the delta heat for water.

Procedure: 1) start with 100ml of water on a hot plate and make sure it is at 50 Celsius

 2) Place into foam cup and record the temperature

 3) Drop 2-3 ice cubes in and stir but don't run out of ice. If ice melts add more

 4) Once temp stabilizes around 0 Celsius and remove ice

 5) Measure new volume of the water

Data Table:

0 minutes 50 Celsius 

1 minute 5 Celsius 

2 minutes 3 Celsius 

3 minutes 3 Celsius 

4 minutes 0 Celsius 

Starting Water: 100g

Ice water with cup: 165.46g

Cup: 7.49

Ice water: 157.97

Calculate: 

1) mass of 100ml of water

 100ml=100g

2) Calculate q = m x delta t x c

q= 100 g x 50 x 50 C= 250,000

3) Determine q ice

flip sign -250,00

4) Mass of ice melted

57.97 g

5) Moles of ice melted

57.97(1 mol/18)= 3.22

6) delta H fusion for ice kj

   3.22           1 mol H2O

250,000jk             x

7) delta H = 6.01 kj/mol

Conclusion:

If 100ml water is cooled to 0 Celsius with ice then the delta H will equal about 6.01 kj/mol because delta H for water is 6.01 kj/mol. This does support the hypothesis. This experiment went well except the cup had a small leak so it had to be plugged with fingers which could have contributed extra heat. Also it never was exactly 0 degrees. This experiment was successful because water was cooled to 0 Celsius the delta heat was found being about 6.01 kj/mol.

P 1154 #22-23 p1158 #14-15

P 1144 and 1148 #13-15

P 1147 #3-4