Measurements of Glassware

Measurement and Proper use of Laboratory Glassware

January 29, 2011

Partners: Shazad Chida

Jennifer Milbery

Beginning Ideas

The key question for lab 1 was, “Which piece of glassware is the most correct?”. Initially it was thought that the volumetric pipette might be the most correct piece of glassware. The reason the volumetric pipette was thought to be the most correct, or most accurate, was because this piece of glassware has a small surface area, therefore making it easier to hopefully get a more precise volumetric reading.

Tests

The first step that was taken to test this hypothesis was to begin with aspirating up 25ml of water in a volumetric pipette and transferring it to a 50ml graduated cylinder.

The second step taken was to try a new approach, by determining the temperature of the water inside of a 250 ml beaker at 25ml and comparing it to the corresponding approximate density of water in g/ml for that temperature.

The third step was to take the weight of the 250ml beaker with the 25ml of water in it and subtract the weight of an empty 250ml beaker; this is known as the mass.

The forth step was to divide the mass by the volume, 25ml, giving us the density of water in the 250ml beaker.

The fifth step was to calculate the density of 25ml of water in a 25ml volumetric flask.

The sixth step was to calculate the density of the water in the 25ml volumetric pipette. There was a transfer of 25ml of water from the volumetric pipette to a 250ml beaker, to make the weighing process easier.

The last step taken was to calculate the density of 25ml of water in a 50ml graduated cylinder.

Observations

After the 25ml of water was transferred from the volumetric pipette to the graduated cylinder, it was noted that the bottom of the meniscus in the graduated cylinder read 26ml. It was later discovered that the temperature of the water sample in the beaker was 25 degrees Celsius and the density of the 25ml of water in a 250ml beaker was discovered...