You have a 0.850 M NaCl solution. What is the concentration of NaCl in mass percent? (The density of this solution is 1.05 g/mL) .

The answer to the question is

The solution contains 4.73 % by mass of NaCl

Explanation:

To solve this we list out the variables thus

The  Molarity of NaCl = 0.850 M,  

Density of solution = 1.05 g/mL

Molar mass of NaCl = 58.44 g/mol

Therefore mass of NaCl in he solution = (58.44 g/mol) × (0.850 M) =  49.674 g of NaCl

However the density = 1.05 g/mL or 1050 g/L

Therefore the mass percent of NaCl in 1 liter of solution or 1050 g of solution = (49.674/1050) × 100 = 4.73 %

The concentration of NaCl in mass percent = 4.73 %

a saline water is fed to a reverse osmosis unit at flow rate o rotameter connected to reject (retentate) line reads 8 installed in reject and permeate line reads 15.2 milli siemens/cm and 300 micro siemens/com respectively.