Lab Questions 1-4 p. 45

1. The reference solution and the blank were used so we could compare the results, and see how the reference reacted and the blank solution reacted.

2. Some possible problems associated with qualitative tests are that the solution could get contaminated,  and the ion could still be present but not visible.

3. The tests cannot absolutely confirm the absence of an ion because some ions are too small and won't show a reaction.

4. How my observations may have changed is that the results would be contaminated with other liquids, and for example, the blank could react when it is not supposed to.