Cesium 2013

Here are your reminders:

CHEM:
- Practical Test again on Monday:
- Problem Set: (to be done on a 1 whole sheet of intermediate pad)

13.30-a:
What is the molality of a solution formed by dissolving 1.50 mol of KCl in 16.0 mol of water?

13.32:
Ascorbic acid, (vitamin C, C₆H₈O₆) is a water-soluble vitamin. A solution containing 80.5 g of ascorbic acid issolved in 210 g of water has a density of 1.22 g/mL at 55°C. Calculate: a) mass percentage; b) mole fraction; c) molality; d) molarity of ascorbic acid in this solution.

13.34:
The density of toluene (C₇H₈) is 0.867 g/mL, and the density of thiophene (C₄H₄S) is 1.065 g/mL. A solution is made by dissolving 10.0 g of thiophene in 250.0 mL of toluene. a) Calculate the mole fraction of thiophene in the solution. b) Calculate the molality of thiphene in the solution. c) Assuming that the volumes of the solute and solvent are additive, what is the molarity of thiophene in the solution?

13.36:
Calculate the number of moles of solute present in each of the following solutions: a) 245 mL of 1.59 M HNO₃(aq); b) 50.0 mg of an aqueous solution that is 1.25 m NaCl; c) 75.0 g of an aqueous solution that is 1.50% sucrose (C₁₂ H₂₂O₁₁) by mass.

PHY:
- Don't forget to answer the problem set. It can be found on the previous posts.

ENG:
- Group reporting again on Wednesday

MATH:



*Comment if I missed/wronged anything.