Experiment 13 Chem 102L

The following freezing temperatures will be recorded in this lab. A. The pure solvent, water B. The pure solvent, stearic acid C. The solution of stearic acid with water D. The pure solvent, unknown acid E. The solution of stearic acid with an unknown fatty acid F. The solution of unknown fatty acid with water

B. The Pure solvent, stearic acid E. The solution of stearic acid with an unknown fatty acid

The main purpose for Experiment 13: Colligative Properties is to A. experimentally determine what the definition of molality is B. to identify an unknown acid dissolved in stearic acid through the colligative property of freezing point depression C. define what a colligative property is D. Navigate through the procedure and collect data

B. to identify an unknown acid dissolved in stearic acid through the colligative property of freezing point depression

A solution containing 20.0 g of an unknown non-electrolyte liquid and 110.0 g water has a freezing point of -1.32 °C. Given Kf = 1.86°C/m for water, the molar mass of the unknown liquid is ____g/mol. A. 28 B. 71 C. 128 D. 256

D.256

Describe the expected experimental apparatus you will use to determine the freezing point of the fatty acid samples. A. Large test tube and a small test tube were clamped over a beaker that have boiling water. The alcohol thermometer was placed in the water to monitor the temperature B. The smaller test tube was required to be wrapped around with a paper towel and fit into the larger test tube. The large test tube was secured on the ring stand using a clamp and it was positioned over the hot plate. A Vernier temperature probe will be placed inside the smaller test tube to record the temperature C. The smaller test tube was required to be wrapped around with a paper towel and fit into the larger test tube. The large test tube was secured on the ring stand using a clamp and it was positioned over the hot plate that contained a water beaker. A Vernier temperature probe will be placed inside the beaker to record the temperature of the water. D. The larger test tube was required to be wrapped around with a paper towel and fit beside the smaller test tube. The large test tube was secured on the ring stand using a clamp and both tubes were positioned over the hot plate that contained a water beaker. An alcohol thermometer was placed inside the beaker to record the temperature. E. The smaller test tube was required to be wrapped around with a paper towel and fit into the larger test tube. The large test tube was secured on the ring stand using a clamp and it was positioned over the hot plate that contained a water beaker. An alcohol thermometer will be placed in the small test tube to monitor the temperature.

E. The smaller test tube was required to be wrapped around with a paper towel and fit into the larger test tube. The large test tube was secured on the ring stand using a clamp and it was positioned over the hot plate that contained a water beaker. An alcohol thermometer will be placed in the small test tube to monitor the temperature.

At different elevations, compounds can have different van't hoff factors. A. Yes! Pressure effects the ability for solute to dissolve in water. B. No, it depends on the identity of the solute. C. No, van't hoff factors are only dependent on the quantity of solute particles. D. Yes! The smaller the boiling point, the more likely ions will dissolve.

No, it depends on the identity of the solute.

True or False: A colligative property depends upon the number of solute molecules present and is not dependent upon the specific chemical identity.

True

True or False: The unknown was added to the same stearic acid sample used in Part C.

True