1. Determine the effect each of following errors would have on your determination of the percentages of the components in your mixture. In each case and for each component, indicate if the error would result in a determination of each substance that is too high, too low, or unchanged. Explain.

a. The residue was washed with tap water instead of deionized water.

1) ammonium chloride:

2) Salt:

3) Sand:

b. The residue from the filtration was not washed.

1) ammonium chloride:

2) Salt:

3)Sand:

c. Some of the mixture splattered out of the dish during the first heating.

1) ammonium chloride:

2) Salt:

3) Sand:

2a. A mixture of just sodium chloride and sand was subjected to a separation much like the one you did in lab. If a 2.1035g mixture was separated to isolate 1.7035g of sodium chloride, and 0.2904g of sand, what is the percentage of sodium chloride and sand in the mixture? (Be sure to report the answer with the correct number of significant figures)

Sand:

Sodium Chloride:

2b. The percentages from problem 2a do not add up to 100%. Provide a reasonable explanation why they do not.

3. Why did we cover the evaporating dish with a watch glass during the evaporation, but not during the sublimation?