A12.34 ml solution with an unknown salt concentration had a mass of 10.25g. when the water was evaporated from the solution 4.78 g of nacl remained. calculate the molarity of nacl in the solution.

Hey there!

Mass of NaCl = 4.78 g

Molar mass of NaCl = 58.44 g/mol

Volume of solution = 12.34 mL

Number of moles:

n = mass of solute / molar mass

n = 4.78 / 58.44

n = 0.08179 moles of NaCl

Volume in liters:

12.34 mL / 1000 => 0.01234 L

Therefore:

Molarity = number of moles / Volume ( L )

Molarity = 0.08179 / 0.01234

Molarity = 6.62 M

Hope that thelps!