Experiment 1

There are several aqueous substances of unknown properties; you set out to determine the unknown densities, in g/ml, of these substances.  You clean a graduated cylinder and weight it.  Then you fill the cylinder with 10.00 ml of each of the unknowns individually.  After that you are able to calculate their weights, and therefore find their densities using the formula "density = mass / volume."  The cylinder weighs 24.50 g, and the weight and volume of each unknown is given in the following table.
 

Compound	Weight of compound and cylinder	ml used
Unknown A	56.32 g	45.5 ml
Unknown B	46.56 g	10.00 ml
Unknown C	89.65 g	17.56 ml

Through running this experiment a second time, you find the following data using the same equipment and unknowns:
 

Compound	Weight of compound and cylinder	ml used
Unknown A	57.55 g	45.5 ml
Unknown B	46.4 g	10.00 ml
Unknown C	90.25 g	17.56 ml

1. The results from the first chart are likely larger values because:
A.  of slight error, uncalibrated scales, etc.
B.  of damage that was done to the scale equipment.
C.  of deterioration of the graduated cylinder.
D.  of the odd miscibility of the substances.

2. In the second chart, which unknown has the highest density, and what is its density?
A.  Unknown A - 1.26 g/ml
B.  Unknown B - 4.64 g/ml
C.  Unknown C - 5.14 g/ml
D.  Unknown C - 3.74 g/ml