Question

3 Severely dehydrated patients may be given a "physiological buffered saline" (PBS) solution with a pH of about 7.4 intravenously to restore thbeir fluid balance Do vou think that PBS would contain only sodium chloride in the solution? Justify your answer. www .4- Honda. Use the dilution equation to calculate the number of milliliters of 3.00 M NaCl needed to make 400.0 mL of a PBS solution with a final sodium chloride concentration of 0.154 M. Show your work. Calculate the molarity of a solution made by dissolving 50.0 grams of KNO, in enough make 250.0 mL of solution. Show your work. 5. water to

Answer 1

3.

Sodium chloride is a salt of strong acid (HCl) with strong base(NaOH). It does not hydrolyze in aqueous solution. Its aqueous solution is neutral with pH 7. pH of PBS is 7.4. It is different from pH 7. Hence, PBS will contain sodium chloride and a suitable buffer solution.

4.

$V_2=\frac{M_1 \times V_1}{M_2}$

$V_2=\frac{ 0.154 \ M \times 400.0 \ mL}{3.00 \ M}$

$V_2=20.5 \ mL$

5.

$\frac{ 50.0 \ g}{101.1 \ g/mol \times 250.0 \ mL} \times 1000 \ mL/L=1.98 \ M$