Solubility Laboratory

Accelerated Studies in Physics and Chemistry Laboratory

Author: Shannon K. Smith

Team Members: Grace Corley, Caroline Kerley, Bryson Thomas

Date of Experiment: March 28, 2011

Date Report Submitted: April 8, 2011

Class: Accelerated Studies in Physics and Chemistry, D block

Mr. Mays, Instructor

Purpose Statement

The purpose of this experiment was to determine how temperature affected solubility and how solubility could be determined by experiment. Two experiments were conducted, one with salt and one with sugar.

Background

To solve for the solubility, the equation of: p = m/v was used, where p is the solubility, and for the purpose of this lab, expressed in g/mL, m is the mass and v is the volume. For all of the volumes, approximately 50 mL of water was used.

The team divided into two separate groups, one for the hot water and the other for cold water. The team measured out approximately 100g of sodium chlorine and 50 mL of water. The sodium chlorine was slowly added it in to the beaker of water and stirred until it started to collect in the bottom of the beaker. The remaining sodium chlorine was measured and subtracted from the original 100g to discover how much sodium chlorine had dissolved into the water. The solubility was calculated. This procedure was repeated with sucrose.

The hypothesis was that in a higher temperature, the solubility would also be higher, despite if the solute was sucrose of sodium chorine.

Experimental Procedure

Equipment and materials used in this experiment were:

support rod (1)

burner ring (1)

right-angle clamp (1)

burner pad (1)

Bunsen burner (1)

gas hose (1)

tongs (2)

scoop (1)

beaker, 250 mL (1)

beaker, 400 mL (1)

electric stirrer (2)

stirring magnet (2)

graduated cylinder, 100 mL (1)

triple-beam balance (1)

sugar

table salt

water

The team divided up into two sections; one for the hot water and one for the cold water. The first step was to measure out approximately 50 mL of tap water into a 100 mL graduated cylinder. After the team measured out the water, it was poured into a 250 mL beaker. Then, approximately 100 grams of sodium chloride into a weigh boat. For the hot water, the team heated up the water until it was approximately 90 degrees Celsius. The team then used the scoop to place small amounts of salt into the beaker of water. The water was then stirred with the magnetic stirrer. This process was repeated until grains of sodium chloride started to accumulate at the bottom of the beaker. At the first sign of this, the leftover salt was measured and subtracted from 100 grams to get the amount that had dissolved into the water. If it was the hot water, the temperature was taken and if it was under 70 degrees Celsius, it was heated back up until it as at least 70 degrees Celsius. If there were still grains of sodium chloride at the bottom, the leftover sodium chloride was measured but if it had dissolved, more sodium chloride was added until they accumulated at the bottom. The solubility was calculated using This process was repeated with the sucrose.

Results

The results for this experiment are shown in Table 1.

solute	solubility
sucrose: 90 degrees C	.78 g/mL
sodium chloride: 90 degrees C	.292 g/mL
sucrose: 20 degrees C	.902 g/mL
sodium chloride: 20 degrees C	.364 g/mL

Discussion

The team’s results are represented graphically in Graph 1. The hypothesis was that the higher temperature of water would have a higher solubility than the cold water but in Graph 1 it shows that the sucrose had a higher solubility, despite the temperature. Referring to the purpose of this lab, the team’s results show that the temperature does not affect the solubility.

The possible sources of error consist of human error. Since the team had a limited amount of time to complete the lab, there were possible errors made from being rushed. When mixing the water and the solute, small amounts of water spilled out of the beaker, so the measurements were not exact. Also, the 100 grams of sucrose or sodium chlorine were only approximate measurements.

X axis- temperature, deg. C

Y axis - solubility g/mL

Conclusion

The team’s results were definitive; sucrose has a higher solubility than sodium chlorine. The higher temperature of the water does not mean that the solubility will be higher. The team’s hypothesis was disproved and temperature differences does not affect the solubility.

References

1. The Student Lab Report Handbook, 2nd ed. (Novare Science and Math: 2010)
2. Mays, John D. ASPC; Accelerated Studies in Physics and Chemistry: A Mastery - Oriented Curriculum for Ninth Grade, Preliminary Draft Version. (Novare Science and Math: 2011)