Question

PHARMACEUTICS CLASS

Question 1:

The activity of sodium ions in a 0.10 M solution is 0.079M. What percentage of ions in this solution is free? Write numerical answer only; round to nearest percentage.

Question 2:

Calculate the ionic strength of a solution that contains 0.184 M NaCl, 0.318 M CaCl₂, 5% w/v dextrose (mw = 180.16 g/mol), and 0.021 M FeCl₃. Report answer to three decimal places (with leading zeros as appropriate). Do not type units into answer field (assume M).

Question 3:

Calculate the mean activity of CaCl₂ ions in a 1% w/v solution that also contains 0.154 M NaCl.  Assume that the molecular weight of CaCl₂ is 110. 98 g/mol, and that the use of the Extended Debye-Huckel Equation is appropriate at all μ > 0.100 M Report final answer to 3 decimal places (with leading zeros as appropriate). Do not include units in answer (assume M).

Question 4:

Calculate the freezing temperature of a 0.88 m dextrose solution (mw = 180.16 g/mol), assuming a cryoscopic constant of 1.86 K/m. Report answer to 2 decimal places (with leading zeros as appropriate). Do not include units with answer (assume ^oC).

Question 5:

Calculate the vapour pressure of an aqueous solution containing 83 g of NaCl (mw = 58.44 g/mol) in 882 g of water. Assume the degree of dissociation of NaCl is 88% and that the vapour pressure of pure water is 3.17 kPa. Report answer to two decimal places (with leading zeros as appropriate). Do not include units in answer (assume kPa).

Question 6:

Calculate the mean activity coefficient for a 0.143 m solution of randomycin potassium in the presence of 0.106 m NaCl. Randomycin potassium is a 1:1 drug salt with a mw =245.69 g/mol. Report answer to 3 decimal places (with leading zeros as appropriate).

Answer 1