1. Energy and Water Page 427-434

2. 30% of the Earth’s surface is land. 70% of the Earth’s surface is water.

3. Solar radiation on the oceans have a major influence on weather. A more appropriate name for “planet Earth” is “planet water”.

4. Snow reflects 90% of the incoming radiation. Ice reflects 50% of incoming radiation.

5. Water reflects 7%7%7%7% of incoming radiation. Therefore, lakes, rivers and oceans absorb 93% of the incoming radiation.

6. The temperatures of the oceans and very large lakes are relatively constant for several reasons. 1.specific heat capacity 2.heat of vaporization 3.heat of fusion

7. 1. Specific Heat Capacity Specific heat capacity (c) is the amount of heat (Q) taken in or given off, to change the temperature (ΔT) of one gram of a substance (m) one degree Celsius.

8. In short: Specific heat capacity is the number of joules per gram per degree Celsius. Or: Specific heat capacity = #Joules(J) (1 g) x (1ºC) (1 g) x (1ºC)

9. Using the formula: Q = mcΔT you can calculate the amount of heat/energy (Q)(Q)(Q)(Q) required to raise the temperature of a substance (m)(m)(m)(m) by a given temperature change (ΔT).

10. Certain substances and their calculated Specific Heat Capacities Substance Specific Heat Capacity (J/gºC) Water (pure) 4.18 Sea water 3.89 Dry air 1.00

11. Wet mud 2.51 Brick0.84 Granite0.79 Limestone0.92 Methanol2.55 Ethanol2.46 Hexane2.26 Toluene1.80

12. Lead0.13 Copper0.39 Iron0.45 Aluminum0.90 Heavy oil 2.1 Ice2.1

13. Question Compare the increase in the temperature of 1.0 g of water and 1.0 g of ethanol when they each absorb 10 J of thermal energy.

14. Solution Use the formula Q = mcΔT For water: Q = mcΔT 10 J = 1.0 g x 4.18 J/ gºC x ΔT 10 J = ΔT 10 J = ΔT 4.18ºC 4.18ºC ΔT = 2.4ºC ΔT = 2.4ºC

15. For ethanol: Q = mcΔT 10 J = 1.0 g x 2.46 J/ gºC x ΔT 10 J = ΔT 2.46 ºC ΔT = 4.1º C

16. Paraphrase of the solution When 1.0 g of water absorbs 10 Joules of energy, the temperature increases by 2.4º C.

17. When 1.0 g of ethanol absorbs 10 J of energy, the temperature increases by 4.1ºC. Therefore, the temperature of ethanol increases more than the temperature of water, under the same conditions.

18. The End