In a laboratory experiment, a 18.0 ml sample of NaCl solution is poured into an evaporating dish with a mass of 24.00 g. The combined mass of the evaporating dish and NaCl solution is 37.15g. After heating, the evaporating dish and dry NaCl have a combined mass of 26.50 g.

Question

If water is added to 18.0 ml of the initial NaCl solution to give a final volume of 80.0 ml, what is the molarity of the dilute NaCl solution?

Answer 1

(Initial Molarity of NaCl)(Initial Volume of NaCl solution)=(?)(Final Volume of diluted solution)

Answer 2

e.d. = evaporation dish = 24.00
mass e.d. + mass H2O + mass NaCl = 37.15g
mass e.d. + mass NaCl = 26.50
Subtract and mass H2O = 10.65
Then 24.00 + 10.65 + mass NaCl = 37.15
mass NaCl = 2.50 g
moles NaCl = grams/molar mass
M NaCl = moles NaCl/0.080 L = ??