- 1) Predict whether each of these substance would be more soluble in water (polar solvent) or benzene (nonpolar solvent)
- Olive oil (non polar)
- Ethanol or grain alcohol ( polar)
- Table Salt or NaCl (ionic)
- Sugar (Polar covalent)
- 2) Compare the processes that occur when potassium chloride, barium hydroxide and hydrobromic acid (HBr) dissolve in water. Write out the equation and make a sketch of what is happening.
- 3) What is the expected conductivity of electricity of each of these substances?
- Acetic acid (Vinegar)
- Butane (C4H8)
- Ammonia (NH3)
- 4) At standard pressure (1 atm) and 0°C, diatomic oxygen (O2) can dissolve in water at a rate of 0.70 g/ 1 L of water. At the same temperature, but at a new pressure of 0.25 atm, how much oxygen can dissolve in water?
- 5) Calculate mole fraction for each of these solutes and solvents:
- 120 g of NH4NO3 in 300 g of water
- 25g of Br2 in 150 g of ethanol, C2H5OH
- 25g of NaCl in dichloromethane, CH2Cl2
- Methanol, Ethanol and water in a solution that is 35% methanol, 40% Ethanol and 15% water
- 6) Practice calculating molarity:
- 875 g of H2SO4 in 2kg of water
- Cyanic acid (HCN) in a solution that is 74% HCN by mass
- A 26% solution (mass) of potassium carbonate (K2CO3) with a density of 1.09 g/cm3.
- 7) Predict which compound would depress freezing point the most, and explain why:
- NaCl
- Glucose
- Na2CO3
- 8) If a solution of MgBr2 in water freezes at -1.28°C, what is the boiling point of the solution?. Assume ideal solution behavior.
- 9) Explain two major differences between colloids and solutions.
- 10) How would you prepare a 4.5 m aqueous solution of glycerol (C3H8O3)? Calculate freezing point for this solution. This is often used by scientists to freeze bacteria- why might this molecule be a good choice?