Question

Calculate the molarity of sodium chloride in a half-normal saline solution (0.45% NaCl). The molar mass of NaCl

Answer 1

Answer:

0.077 M

Explanation:

Molarity is the representation of the solution.

Molarity:

It is amount of solute in moles per liter of solution and represented by M

Formula used for Molarity

                    M = moles of solute / Liter of solution . . . . . . . . . . (1)

Data Given :

The concentration of half normal (NaCl) saline = 0.45g / 100 g

So,

Volume of Solution =  100 g = 100 mL

Volume of Solution in L =  100 mL / 1000

Volume of Solution =  0.1 L

molar mass of NaCl = 58.44 g/mol

Now to find number of moles of Nacl

               no. of moles of NaCl = mass of NaCl / molar mass

               no. of moles of NaCl =  0.45g / 58.44 g/mol

               no. of moles of NaCl =  0.0077 g

Put values in the eq (1)

                  M = moles of solute / Liter of solution . . . . . . . . . . (1)

                  M = 0.0077 g / 0.1 L

                  M = 0.077 M

So the molarity of half-normal saline solution (0.45% NaCl) = 0.077 M