Thermo Review

Heating Curves

100

Draw  heating curve with a freezing temperature of 40 degree C

.

200

Draw a cooling curve with a condensation temperature of 100 C

.

300

How much energy is required to heat 45g of water from 26.5 C to 78.8 C?

2,400 cal

400

How much energy is released when condensing 365 g of steam?

Hvap = 540 cal/g

Hfus = 80 cal/g

197,000 cal

500

How much heat is required to turn 15g of ice at -5.0 C to steam at 125 C?

Hvap = 540 cal/g      Hfus = 80 cal/g

Cice = 0.5  Cwater = 1  Csteam = 0.48 (cal/gC)

11,000 cal

Conservation of energy

100

Heat transfers from hot to ______

Cold/Cool

200

A 200 gram piece of silver is cooled from 125°C to 35°C by dropping it in 125 grams of water.  The temperature change of the water is ______

(c of silver is 0.0558 cal/gC)

8 C

300

A 30.00 gram sample of an unknown metal was removed from boiling water at 100.0°C and placed in a calorimeter containing 100.00 grams of water at 20.0°C. The final temperature of water and metal was 22.4°C. Calculate the specific heat of the unknown metal. 

0.103 cal/gC

400

A 565g cube of iron is cooled from 100.°C to 25.°C by dropping it in water at 10.°C. The volume of water needed is _____. 

(c of iron is 0.11 cal/gC)

310 mL

500

An 8.0g iron ball is placed on a block of ice at 0.0 C, 2.0g of ice melts. What is the initial temperature of the iron ball?

(c of iron is 0.11 cal/gC)
(c of water is 1 cal/gC)
(Delta Hfus of water is 80 cal/g)

180 C

Delta H

100

The sign (+ or -) of delta H for an endothermic reaction

+

200

The delta H of:

N2(g) + 2 O2(g) --> 2 NO2(g) 

66.2 kJ/mol

300

C3H8(g) + 5O2(g) --> 3CO2(g) + 4H2O(g)

-2,043 kJ/mol

400

Determine the  delta Hf of Zn(OH)2(s) in

  Zn(OH)2(s) ---> ZnO(s) + H2O(g) ΔH= +48.0 kJ

-638.1 kJ/mol

500

Draw a potential energy graph for the combustion of methane. Include the delta H value in the graph.

H = -802.3 kJ/mol

Hess's Law

100

BaO(s) + H2SO4(aq) ---> BaSO4(aq) + H2O (l)  

ΔH = ?

  BaO(s) + SO3(g) ---> BaSO4 (aq) ΔH = -213 kJ

  SO3(g) + H2O (l) ---> H2SO4 (aq) ΔH = -78 kJ

ΔH = -135

200

CO2(g) ---> C(s) + O2(g) ΔH = ?

  C(s) + CO2(g) ---> 2CO(g) ΔH = 173 kJ

  2CO(g) + O2(g) ---> 2CO2(g) ΔH = -567 kJ

394 kJ

300

2 C3H8 (g) + H2 ---> 3C2H6(g) ΔH = ?

  2C (s) + 3H2(g) ---> C2H6(g) ΔH = -20.2 kcal

  3C(s) + 4H2(g) ---> C3H8(g) ΔH = -24.8 kcal

-11 kcal

400

N2(g) + O2(g) ---> 2NO(g)      ΔH = ?

4NH3(g) + 3O2(g) ---> 2N2(g) + 6H2O(l) 

 ΔH = -1530 kJ

4NH3(g) + 5O2(g) ---> 4NO(g) + 6H2O (l)
 ΔH = -1170 kJ

ΔH = 180 kJ

500

C3H6 (g) + H2 (g) ---> C3H8(g)  ΔH = ?

2H2(g) + O2(g)---> 2H2O(l) ΔH = -572 kJ

C3H6(g) + 4.5O2(g) ---> 3H2O(l) + 3CO2(g) 

ΔH = -1225 kJ

C3H8(g) + 5O2(g) ---> 4H2O (l) + 3CO2(g) 

ΔH = -2043 kJ

ΔH = 532 kJ

Heat Stoichiometry

100

Fe2O3 (s)+ 3 CO (g) --> 2 Fe(s) + 3 CO2 (g) + 6,600 cal 

Exothermic or endothermic?

Exothermic

200

Fe2O3 (s)+ 3 CO (g)  2 Fe(s) + 3 CO2 (g) + 6,600 cal 

How much energy is produced when 3.00 mol of Fe2O3 react?

19,800 cal

300

Fe2O3 (s)+ 3 CO (g) --> 2 Fe(s) + 3 CO2 (g) + 6,600 cal 

How much energy is produced when 28g of iron is produced?

1700 cal

400

19.5 kcal + Br2 (l) + I2 (s) --> 2 IBr (g)

How much energy is required to create 45.0g of IBr(g)?

2.12 kcal

500

6 CO2 (g) + 6 H2O(g)  C6H12O6 (s) + 6 O2 (g) 

 ΔH = +673 kcal

How much energy is needed to have 50.0g of CO2 react with 50.0g of H2O?

127 kcal