Homework 6/25

Page 52 #25-34

25. Qualitative tests identify the presence of a particular substance, and quantitative tests determine the amount of a substance.

26. A confirming test is a positive test that confirms that the ion is present.

27. A) The reference solution is a solution of a known composition used as comparison.

B) The distilled water blank is another solution that is known not to contain any ions of interest

28.  Iron dissolves in water so one would not be able to see the iron, but it could still be there.

29. A) One would have to see if the mixtures have any remaining solids in the substance, see if the suspension is separated, or if it is a thoroughly mixed solution with no additional colloids or oils.

B) You can tell my seeing if there are any solid particles in the substance.

30. The possible effects of not shaking the bottle before using it could be a not separated solution, which means that the mixtures are a suspension and not thoroughly mixed together, causing an unwanted liquid result.

31. It is useful because scientists in America can understand other scientists around the world, and we can use the SI system, which is extremely helpful.

32.

33. No, it is impossible for water to be 100% chemical free because there will always be outside substances, such as water vapor and carbon that will enter the water. There are also necessary minerals in the water that cannot be removed.

34.  Water (H₂O) is a liquid as opposed to hydrogen and oxygen separately, which are gases. Water is also denser then the two gases, and has a larger mass.