Question

A 0.150 M sodium chloride solution is referred to as a physiological saline solution because it shares the same concentration of salts as normal human blood. Calculate the mass of solute needed to prepare 275.0 mL if a physiological saline solution.
a. 2.41 g
b. 31.9 g
c. 8.77 g
d. 41.3 g

Answer 1

Answer:

2.41 g of NaCl is needed

Explanation:

Molarity of solution = (Number of moles of solute)/(Volume of solution in Litre)

Here sodium chloride (NaCl) is solute in saline solution

275 mL = 0.275 L

So, number of moles of NaCl in 275 mL saline solution  = $(0.150\times 0.275)moles=0.04125moles$

Molar mass of NaCl = 58.44 g/mol

Number of moles = (mass)/(molar mass)

So, mass of 0.04125 moles of NaCl = $(0.04125\times 58.44)g=2.41$

So, 2.41 g of NaCl is needed