Chemistry-GeneralName :
Worksheet : Ch. 15 and 16 : Obj. 1-10Date :
A. Read pp. 486 - 497 and answer the following questions.
1. _____(T/F) The O-H bonds of the water molecule are ionic bonds and are nonpolar.
2. _____(T/F) The bond angle between the two O-H bonds is 105 degrees.
3. _____(T/F) The water molecule is polar, with the oxygen end of the molecule being negative and the hydrogen end being positive.
4. _____(T/F) The oxygen atom of the water molecule is less electronegative than the hydrogen atoms making it have a higher attraction for electrons than the hydrogen atoms.
5. Name two van der Waal's forces which cause water molecules to attract each other and state which is the stronger force.
6. _____ (T/F) Water has the following five properties because it is a nonpolar molecule.
- high heat of vaporization
- high boiling point
- high surface tension
- high heat capacity (takes a lot of energy to change its temperature)
- low vapor pressure
7. ______is the inward pull of a liquid due to the attraction of the molecules for each other
8. ______are agents which interfere with the hydrogen-bonding between water molecules and reduce surface tension.
9. _____(T/F) The hydrogen bonding of water molecules increases the capacity for water molecules to leave the liquid state to become a gas (vaporize) and causes water to have a high vapor pressure.
10. _____(T/F) Water has a high heat capacity, meaning that its temperature is slow to change compared to many other substances.
11. _____(T/F) Water has a high heat capacity because the heat energy added goes directly into increasing the average kinetic energy of the water and not to overcoming intermolecular attractive forces such as dipole interactions and hydrogen bonding.
12. _____(T/F) Water has a low heat of vaporization because it takes little energy to cause one water molecule to escape from another water molecule.
13. _____ (T/F) The earth’s climate is moderated (prevented from fluctuating too much) because water has a very high heat capacity and the greater percentage of the earth is covered in water.
14. _____(T/F) Water is a liquid at room temperature because of hydrogen bonding.
15. _____(T/F) Liquids typically become more dense as they cool.
16. _____(T/F) Water has its greatest density at 4 ºC.
17. _____(T/F) If ice were more dense than liquid water lakes would freeze from the bottom up killing many of the lake's aquatic species.
18. ______solutions are solutions in which water is the solvent.
19. _____(T/F) Solutions are homogenous mixtures which will not settle out over time.
20. Name two types of solutes that will readily dissolve in water and one that will not readily dissolve in water.
21. Explain the process of solvation.
22. _____(T/F) When the attractive forces between the ions of an ionic compound are greater than the attractive forces of water the ionic compound will not dissolve.
23. Explain the general rule "like dissolves like."
24. Which of the following compounds are likely to be very soluble in water?
NaF O2 CaCO3 oil CH4 (methane) MgCl2