## Pharmaceutics Calculations Practice Set #11 with Answers

Question 1
Phenylephrine HCl 1%
Purified water qs 30 mL
Make isotonic solution
Given: ΔTf,1% (NaCl) = 0.58
ΔTf,1% (P.H.) = 0.18
How many grams of NaCl should be added?
A. 0.586
B. 0.310
C. 0.176
D. 0.093

Question 2
Pilocarpine nitrate 1%
Purified water qs 50 mL
Make solution isotonic
Given: ΔTf,1% (NaCl) = 0.58
ΔTf,1% (P.N.) = 0.14
Calculate the amount of NaCl in mg needed to make the solution isotonic.
A. 328
B. 655
C. 241
D. 121

Question 3
How many milligrams each of NaCl and dibucaine HCl are required to prepare 30 mL of a 1% solution of dibucaine HCl isotonic with tears?
A. 45 & 23
B. 76 & 30
C. 0.228 & 0.3
D. 228 & 300

Question 4
Procaine HCl (MW = 273) is a 2 ion electrolyte, dissociating 80%
Calculate the dissociation factor (i) NaCl equivalent (E)
A. 1.8 & 0.21
B. 2.4 & 0.29
C. 2.4 & 0.32
D. 1.8 & 0.29

Question 5
Calculate the NaCl equivalent of 1% zinc chloride solution (MW = 136; i = 2.6).
A. 0.21
B. 0.62
C. 0.44
D. 0.32

Question 6
Calculate the sodium chloride equivalent for fluorescein sodium, which dissociates into three ions and has a molecular weight of 376.
A. 0.45
B. 0.41
C. 0.32
D. 0.22