SCH 4U
Heating Curve of a Pure Substance
Q
b.p.
1
= m∆TC
Q
2
= ml f
melting
begins
m.p.
Q
3
= m∆TC
solid solid/liquid liquid
Time
Q
4
= ml v melting ends boiling begins
liquid/vapour
Q
5
= m∆TC boiling ends
vapour
1. How much heat energy is gained by 50.0 g of mercury when its temperature rises from 20.5
o C to 60.5
o C? [276 kJ]
2. Calculate the quantity of heat required to melt 100 g of ice at an initial temperature of –15 o C.
[36.7 kJ]
3. Determine the heat energy needed to convert 80 g of ice at –30 o C into steam at 150 o C.[255 kJ]
4. An experiment was performed using an aluminum type calorimeter and the data are shown below. Determine the specific heat capacity of the metal.
mass of calorimeter
mass of metal
= 100g T
= 200g i
(metal)
T i
= 95.0
o C
(calorimeter and water)= 15.0
mass of calorimeter and water = 200g
specific heat capacity (calorimeter)
T f
(mixture)
= 895 J/(kg· o C) [0.384 J/(g· o
= 25.5
C)] o C o C
5. A mass of 200 g of mercury at 113 o C is mixed with an unknown mass of water at 18 o C that is placed in a calorimeter. The mass of the calorimeter is 100 g and its specific heat capacity is
0.920 J/(g· o C). If the final temperature is 23 o C, determine the mass of water in the calorimeter.
[0.097 kg]
6. A mixture is made by adding 120 g of water at a temperature of 80 o C to 75 g of methanol at a temperature of 20 o C. Determine the final temperature of the mixture. (use specific heat capacity of methanol = 2.50 kJ/(kg o C)) [64 o C]

1. 2 Fe(s) + 3/2 O
2
(g)  Fe
2
O
3
(s) + 824 kJ
Write a thermochemical equation (2 ways) for the formation of 2 moles of Fe
2
O
3
.
2. 2 H
2
(g) + O
2
(g)  2 H
2
O(l) ∆H = -571.8 kJ
Determine the mass of hydrogen required to produce 775 kJ of energy [5.46 g]
3. CH
4
(g) + 2 O
2
(g)  CO
2
(g) + 2 H
2
O(l)
When 1.00 g of methane burns, 55.6 kJ were produced. a) Determine the enthalpy change for this reaction. b) Write a thermochemical equation for this reaction.
[∆H = - 892 kJ]
4. Convert the specific heat capacity of aluminum from 0.895 J/(g o C) to J/(K mol) [24.1]
5. If at 25.0
o C, 15.70 g of carbon dioxide absorbs 1.20 kJ, determine the final temperature of the
gas. Its molar heat capacity is 37.11 J/(K mol). [116 o C]
6. A 50.0 g piece of aluminum is heated to 100.0
o C and then put into a beaker containing 150.0
mL of water at 20.0
o C. Assuming no loss of heat to the surroundings, determine the final
temperature of the water. [25.3
o C]
7. A copper calorimeter has a mass of 305 g and contains 255 g of water. When 1.00 g of 1
propanol is burned, the calorimeter and contents increase in temperature by 28.8
thermochemical equation for this reaction. [∆H = -2.05 x10 3 kJ] o C. Write a
8. A 135 g sample of dilute hydrochloric acid (excess reactant) is placed in a copper calorimeter
with a mass of 465 g. The temperature of the acid and calorimeter is 11.7
aluminum metal reacted with the acid, the final temperature was 22.3
o o C. After 5.00 g of
C. Assuming that the
specific heat capacity of the acid solution is equal to that of water, determine the enthalpy
change for the reaction:
2 Al(s) + 6 HCl(aq)  2 AlCl
3
(aq) + 3 H
2
(g) [∆H = -87.4 kJ]
9. A student placed 50.0 mL of 2.05 mol/L NaOH in a coffee-cup calorimeter at 20.4
added 50.0 mL of 1.20 mol/L H
2
SO
4
also at 20.4
o o C, and
C. After quickly stirring the mixture, its temperature rose to 28.2
o C. Determine the enthalpy change for the reaction:
2 NaOH(aq) + H
2
SO
4
(aq)  2 H
2
O(l) + Na
2
SO
4
(aq) [∆H = -63.7 kJ]
1. Titanium metal is used as a structural material in many high-tech applications such as jet
engines. What is the specific heat capacity in J/(g o C) of titanium if it takes 179.4 J to raise the
temperature of a 35.0 g sample by 11.0
o C?
What is the molar heat capacity in J/(mol o C)
[0.466]
[22.3]
2. When 2.090 g of CaO were added to 100.0 mL of water at 22.5
29.8
o C. Determine the enthalpy change for the reaction:
CaO(s) + H
2
O(l)  Ca(OH)
2
(aq) ∆ H = ? kJ o C, the temperature rose to
[-83.5 kJ]
3. Determine the energy released in the reaction of 1.00 g of sodium with water.
2 Na(s) + 2 H
2
O(l)  H
2
(g) + 2 NaOH(aq) ∆ H = -368.4 kJ [8.01 kJ]

4. How much will the temperature of a 180 g cup of coffee at 95
spoon at 25 o C be reduced when a 45 g silver o C is placed in the coffee? The specific heat capacity of silver is 0.24 J/(g o C) [1.0 o C]
5. The body generates energy from food and fats by the same overall process as combustion.
Determine the energy per gram of glucose, C
6
H
12
O
6
, and the energy per gram of glyceryl
trimyristate (a fat), C
45
H
86
O
6
.
C
6
H
12
O
6
(s) + 6 O
2
(g)  6 CO
2
(g) + 6 H
2
O(l) ∆ H = -2803 kJ
C
45
H
86
O
6
+ 63.5 O
2
(g)  45 CO
2
(g) + 43 H
2
O(l) ∆ H = -27 820 kJ
[ 15.6 kJ/g; 38.5 kJ/g]
6. When 15.3 g of sodium nitrate were dissolved in water in a coffee-cup calorimeter, the temperature
fell from 25.00 to 21.56 o C. Determine the mass of water in the calorimeter.
NaNO
3
(s)  Na + (aq) + NO
3
(aq) ∆ H = + 20.5 kJ [241 g]