Determination of Unknown Density Lab

Lab Partner: Kelsee Rieghman

I. Objectives/Purpose

During this particular lab experiment I expect to determine the density of both a liquid and a solid to find out what the unknown substances are by matching it’s density with one of the densities of the 3 metals listed in our packet, and also determine what the unknown liquid will be based on its density and the given information in our packet.

II. Safety Precautions

The liquids used in this experiment may be highly flammable. No sparks or open flames. We will avoid breathing fumes from these liquids and keep them covered and in the fume hood whenever possible. Safety glasses or goggles will be worn at all times as well as effective hand washing.

III. Experimental Procedure and Data

My lab partner and I attempted to obtain as close to a 2.5g sample of the unknown solid as we could.

We then weighed a weighing boat, weighed the sample of the solid while on the weighing boat and subtracted the two to find the mass of the unknown solid.

Next, we filled a graduated cylinder to 5ml, as both partners verified.

Then, we carefully placed the unknown sample into the cylinder to record the amount of water being displaced.

The difference in the two would then determine the volume of the unknown.

To obtain the density use the formula: D=m/v

Trial

Mass Weighing Boat (g)

Mass Boat + solid (g)

Mass solid (g)

Volume solid (ml)

Density (g/ml)

% of Error

1

0.3470g

2.8534g

2.5064g

0.9ml

2.785g/ml

3.15%

2

0.0229g

2.5788g

2.5559g

0.9ml

2.839g/ml

5.15% Using the information charted, my lab partner and I found it safe to say that we concluded that the unknown solid would be Aluminum given that the accepted density was 2.70g/ml.

Next, we moved on to find the density of the unknown liquid.

We rinsed the pipet with the unknown liquid to ensure that all water inside the pipet would be gone.

Next, we obtained the mass of an empty but corked 50ml Erlenmeyer flask on an analytical balance.

We then used the pipet to place 10ml of the