Chemistry Lab writing

Colligative Properties & Osmotic Pressure

Sung Kim

CHM 151

Data Table 1: Pure Water and Salt Solution

Questions Part 1

a. The graph shows the temperature on the left with the time (s) on the x-axis. The color shows the difference between the distilled H2O and the saltwater.

b. The two compares pretty similar but the saltwater was more direct in getting to a constant temperature. Distilled water took a little more time as experienced the super cool as the temperature reached down to -2 Celsius before returning back up to 0.

c. Knowing the depression in freezing point, we can add an anti-freeze to the car to prevent the car fuel from freezing. The antifreeze also causes an elevation in the boiling point, so it helped with a car overheating in the summer. So antifreeze can be a prime example of the freezing point depression and boiling point elevation.

Questions Part 2

a. The dialysis bag is comparable to that of the cell membranes in the kidney. Dialysis is using a membrane as a filter to separate waste from blood. Dialysis tube removes waste materials from a patient’s blood by passing it through the kidney and it overall improves the kidney functions and the overall health of the body.

b. We have a hypertonic solution because we have more solid on the outside of the cell. Pure corn syrup is a hypertonic solution because it has more solids than water. This solution causes the cell to shrivel and decrease in size, which is what we observed as the egg collapsed.

c.

Problem for Lab Report:

At 23.6°C, 0.500 L of a solution containing 0.302 grams of an antibiotic has an osmotic pressure of 8.34 mmHg. What is its molecular mass?

Lets use the formula n=MRT

8.34 mmHG(1 atm/760mmHG) = .010974 atm

.010974 atm [(0.0821L.atm/K.mol)(296.6K)] = .000451 mole/L

.500L(.000451 mole/L) = .000225 mole of antibiotic

Molar mass of antibiotic = .302 gram/.000225 = 1342.22g/mol

Distilled H2O Room Temp 0.0 30.0 60.0 90.0 120.0 150.0 180.0 210.0 240.0 270.0 300.0 330.0 360.0 390.0 420.0 450.0 480.0 510.0 540.0 570.0 600.0 630.0 660.0 22.0 Distilled H2O Ice Bath 0.0 30.0 60.0 90.0 120.0 150.0 180.0 210.0 240.0 270.0 300.0 330.0 360.0 390.0 420.0 450.0 480.0 510.0 540.0 570.0 600.0 630.0 660.0 21.0 5.0 0.0 -1.0 -1.0 -2.0 -1.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Saltwater Room Temp 0.0 30.0 60.0 90.0 120.0 150.0 180.0 210.0 240.0 270.0 300.0 330.0 360.0 390.0 420.0 450.0 480.0 510.0 540.0 570.0 600.0 630.0 660.0 22.0 Saltwater Ice Bath 0.0 30.0 60.0 90.0 120.0 150.0 180.0 210.0 240.0 270.0 300.0 330.0 360.0 390.0 420.0 450.0 480.0 510.0 540.0 570.0 600.0 630.0 660.0 22.0 7.0 4.0 1.0 -1.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0