Homework #10

Questions #9-27, 33, 35

9.  .2 x 55= 11
     55 - 11= 44

10. 15,000

11. Polar molecules are partially negative and positive so a water molecule (having a V-shape) has one oxygen end (which is negative) and two hydrogen ends (which are negative).

12. 

13. A. K+ ion: oxygen (negative) end

      B. Br- ion: hydrogen (positive) ends

14. Their atoms have greater masses than those of essential metallic elements.

15. They include damage to to the nervous system, brain, kidneys and liver, which can even lead to death. They also bind to proteins and prevent them from performing their normal tasks.

16. A. Lead: people get water through lead water pipes connecting to households (but cause lead poisoning). And they also have lead cooking vessels.
      B. Mercury: it's an electrical conductor and used as thermometers.

17. Hydroxide

18. Hydrogen

19. A. Base
      B. Base
      C. Acid
      D. Neutral

20. A. Soft drink

      B. Black coffee

      C. Milk of magnesia

21. 2.0 more times acidic.

22.  1. When pH is too low in rivers, lakes, or streams, fish-egg development is impaired causing hampering the ability of fish to reproduce. 

       2. Bodies of water with low pH values tend to increase the concentrations of metal ions in natural waters by leaching metal ions from surrounding soil, which are toxic.

       3.  High pH is a problem for living organisms because alkaline solutions are able to dissolve organic materials, including skin, and scales.

23. Polar molecules tend to dissolve readily in polar solvents, but nonpolar liquids are good solvents for nonpolar molecules. 

24. Lamp oil because oils readily dissolve in nonpolar body oils.

25. Oil cannot separate causing the salt not to separate. Water on the other hand is polar, so the salt can dissolve.

26. A rule that tells why polar substances dissolve in polar solvents and nonpolar substances dissolve in nonpolar substances. It also tells why nonpolar liquids are usually ineffective in dissolving ionic and polar molecular substances.

27. Water and grease don't mix together well, so soap is needed to clean the grease.

33. A. Nonpolar substances

      B. There are other chemicals in the cleaner that can clean hands for thoroughly than water.

35. Hydrogen because hydrogen has a +1 charge, while Fluorine has a -1 charge.