1. Test tomorrow. All assignments will be due.
Water
In-Class Review

2. 1. What kind of bond holds a water molecule’s hydrogens and oxygen together?

3. 1. What kind of bond holds a water molecule’s hydrogens and oxygen together?
Covalent bond

4. 2. What kind of bond is the attraction of adjacent water molecules for one another?

5. 2. What kind of bond is the attraction of adjacent water molecules for one another?
Hydrogen bond

6. 3. What causes the high surface tension of water?

7. 3. What causes the high surface tension of water?
Hydrogen bonding. (At the surface all hydrogen bonding is aimed in the same direction – down – making it harder to break through)

8. 4. What effect do detergents have on surface tension?

9. 4. What effect do detergents have on surface tension?
Reduces surface tension

10. 5. What is surface tension, in terms of force?

11. 5. What is surface tension, in terms of force?
The amount of force needed to break through a surface

12. 6. Why does ice float

13. 6. Why does ice float
It’s less dense than liquid water

14. 7. What causes the expansion of water as it freezes and results in lower density of ice?

15. 7. What causes the expansion of water as it freezes and results in lower density of ice?
The alignment of hydrogen bonds

16. 8. Based on its size, in what physical state should water be at room temperature?

17. 8. Based on its size, in what physical state should water be at room temperature?
Gas

18. 9. Why is water a liquid and not a gas at room temperature?

19. 9. Why is water a liquid and not a gas at room temperature?
Hydrogen bonds make it harder for particles to escape, thus more energy (heat) is needed than would be expected.
(Extra energy is needed to break the hydrogen bonds)

20. 10. What is the term used to describe the amount of heat needed to raise the temperature of 1 g of a substance 1 degree C?

21. 10. What is the term used to describe the amount of heat needed to raise the temperature of 1 g of a substance 1 degree C?
Specific heat

22. 11. In what states of matter is water commonly found on Earth?

23. 11. In what states of matter is water commonly found on Earth?
Solid
Liquid
Gas

24. 12. Why is it difficult to change the temperature of water, compared with many other substances?

25. 12. Why is it difficult to change the temperature of water, compared with many other substances?
High specific heat

26. 13. Is water polar or non-polar?

27. 13. Is water polar or non-polar?

28. 14. Why does water become polluted easily?

29. 14. Why does water become polluted easily?
It’s a great solvent

30. 15. What is the chemical formula of water?

31. 15. What is the chemical formula of water?
H2O