101 
A T/F exercise. Part (d) is true. Convention I activity coefficients are based on an ideal solution (both components follow Raoult’s Law) while Convention II activity coefficients are based on an ideally dilute solution (the solvent obeys Raoult’s Law but the solute obeys Henry’s Law). In part (e) remember that a real (or actual) solution with mole fraction = 1 is not the same as a standard state with mole fraction = 1. The solvent always behaves ideally as X_{A} approaches 1, but a solid solute only behaves ideally (ie, follows Henry’s Law) as X_{B} approaches 0. 
106 
A shorter T/F exercise. This one is just about definitions. 
107 
An exercise in calculating activities, activity coefficients, change in chemical potential, and D_{mix}G for a solution (alcohol/chloroform) that is somewhat nonideal. 
1012 
An exercise in calculating the activity and activity coefficients for the water in two sucrose solutions. Note that g for the solvent water is very close to 1 in part (b) even though the solution concentration is quite high. The solvent may act nearly ideally even if the solute does not. 


1068 
A rough calculation to find out the (very approximate) average distance between ions in a 1 M solution. 
1069 
Thought exercise relating mixing quantities (D_{mix}H, etc.) to intermolecular interactions. 
108 
Calculate activities and activity coefficients for the solvent and solute in a solution of two liquids using both conventions. In part (b) the Henry’s Law constant for the solute must be determined. This can be done in a simple way by using the first two points or by extrapolating a tangent to the P_{B} vs. X_{B} curve, but the result will be in error by almost a factor of two. A better way to determine the Henry’s Law constant is to plot P_{B}/X_{B} vs. X_{B} and extrapolate that curve to X_{B} = 0. The simplest way to do this is to use a spreadsheet. In part (c) it is necessary to decide which activity to use for component B. The Convention I activity should be used because it is the two pure liquids that are mixed. 


1024 
An exercise in identifying the ions in some simple salts (review of General Chemistry). 
1035 
An exercise in calculating the ionic strength for a solution of several electrolytes containing ions of different charges (1+/1; 2+/1; 2+/2). This is an important problem because of the role of the ionic strength in the activity coefficients of ions. 
1037 
Exercise in using the Davies equation to estimate activity coefficients for ions. Omit part (c) In part (b) remember that the charges in the Davies equation are for the ions of CaCl_{2} rather than for any of the other ions present. 