Homework #9

25. A qualitative test is a test in order to find the presence or absence of a particular substance in a sample and a qualitative test is a test given to determine how much of a specific substance is present in a sample.

26. A confirming test is a positive or negative test that confirms the presence or absence of the ion in question.

27.

a. The reference solution is a solution where the ion being tested for is present which makes it an example of what a precipitate looks like.

b. The distilled water has an absence of ions, so the water continues to remain clear, and particle free.

28. The student should say that the lack of iron’s presence results in a transparent appearance, or a lack of color change.

29.

a. I After stirring the sample, and checking thorugh the Tyndall effect shows the presence of particles settled at the bottom of the mixture.

b. These large solid particles would make the mixture an example of suspension.

30 The medicine would not work to its potential. If one failed to mix the large, settled particles, one could not get the full strength of the medicine.

31. Its much easier for international scientists to communicate through technology if they all share the same element language.

33. No. Even with the expensive process of distillation, it is impossible to have 100% "chemical free" water. The atmospheric gases, nitrogen, oxygen, and carbon dioxide all exist in water to some degree; they always dissolve into water.