1SCS #20-27,33,35

20.a. a tomato.
     b. pure water.
     c. milk of magnesia. 21. Since there is a tenfold difference between each number on the pH scale, a solution at pH 4.0 is 100 times more acidic than a solution at pH 2.0.

22.1) fish egg development impaired, reproduction harmed.2) increased concentrations of metal ions in natural waters by leaching metal ions from 3) dissolves organic materials, such as scales on fish. 

23. A polar molecule is a molecule with an uneven distribution of electrical charge; each molecule has a partial positive region at one end and a partial negative region at the other end. A nonpolar molecule's distribution of electrical charge is equal throughout, meaning it is balanced at both ends of the molecule. 

24. Ethanol and water are both polar substances, so, to dissolve a nonpolar substance,one would use a nonpolar substance such as, lamp oil. 

25. Since water is an extremely attractive polar molecule, the positive and negative charges of NaCl are "pulled" by the charges of the water molecules. Cooking oil on the other hand, is nonpolar. NaCl doesnt dissolve in cooking oil.

26. Polar substances dissolve in polar solvents and nonpolar substances dissolve in nonpolar solvents. 

27. In order to dissolve the grease, the dishes would need to be washed with a solution composed of nonpolar molecules.

33. a. Nonpolar materials are likely to be found in these cleaners.
b. Using these cleaners would be more effective than washing with water because since water   molecules are polar, they would not dissolve the grease off of the mechanics' hands. 

35. Since fluorine has the highest electronegativity of any element, it would make up the negative end of the polar bond.. Since hydrogen has less negative charges than fluorine, it would have the partial positive charge of the polar bond.