Unit 4 Quiz--Heat Calculations |

__Multiple Choice__ (Choose the best answer.)

**For problems 1 - 3 you will need to use the relationship, Heat = Specific Heat x Mass x ****T.**

- How much energy (in calories and in Joules) will it take to raise the temperature of 75.0 g of water from 20.0
to 55.0
^{o}C? ( Specific Heat = 1 cal / ( g^{o}C ) and 4.184 J / ( g^{o}C ) )2630 cal and 630. J

2630 cal and 1.1 x 10

^{4}J1.1 x 10

^{4}cal and 2630 J630. cal and 2630 J

None of these are correct.

- 350 J are released as ice ( Specific Heat = 2.1 J / (g
^{o}C) ) cools from - 5.0^{o}C to -32^{o}C. What is the mass of ice?0.16 g

6.2 g

4.5 x 10

^{3}g2.0 x 10

^{4}gNone of these are correct.

- A 63.0 g piece of aluminum (Specific Heat = 0.215 cal / (g
^{o}C) ) at 25.0^{o}C is warmed by the addition of 325 calories of energy. Find the final tempearture of the aluminum.49.0

^{o}C240.

^{o}C26.1

^{o}C1.11

^{o}CNone of these are correct.

**For problems 4 - 7 you will need to use the heat of fusion (****H**_{fus}) or the heat of vaporization (**H**_{vap}). - How much energy would be required to melt 15.0 g of ice at 0
^{o}C? H_{fus}= 6.01 KJ/mol90.2 KJ

7.21 KJ

5.01 KJ

0.200 KJ

None of these are correct.

- How many moles of ice at 0
^{o}C could be melted with the addition of 750 KJ of energy? H_{fus}= 6.01 KJ/mol8.0 x 10

^{-3}4.4 x 10

^{-4}2200 mol

120 mol

None of these are correct.

- How much energy would it take to boil 36.0 g of water at 100
^{o}C? H_{vap}= 40.7 KJ/mol81.4 KJ

1470 KJ

1.13 KJ

0.0123 KJ

None of these are correct.

- How many grams of steam could be condensed at 100
^{o}C with the removal of 307 KJ of energy? H_{vap}= 40.7 KJ/mol7.37 x 10

^{-3}g7.54 g

17.1 g

136 g

None of these are correct.

**For problems 8 - 10 you will need to use the heat of fusion (****H**_{fus}) , specific heat, or the heat of vaporization (**H**_{vap}) in combinations with one another. Use the values for**H**_{fus}, specific heat, or**H**_{vap}for water listed earlier in the quiz. - How much energy would it take to melt 30.0 g of ice at 0
^{o}C and warm the resulting liquid to 35.0^{o}C?4.39 KJ

10.0 KJ

14.4 KJ

4400 KJ

None of these are correct.

- How much energy would it take to warm 30.0 g of water at 35
^{o}C to the boiling point and boil all the liquid away?8.20 KJ

76 KJ

8200 KJ

8268 KJ

None of these are correct.

- How much energy would be reqired to melt 10.0 g of ice at 0
^{o}C, warm the resulting liquid to 100^{o}C, and change it to steam at 100^{o}C?3.34 KJ

4.18 KJ

22.6 KJ

4210 KJ

None of these are correct.

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