Question

85.0 mL of 1.50 mol/L ammonium chloride solution is added to 250 mL of water. Calculate the molar concentration of the final solution

The answer on the sheet says 0.381 mol/L but I keep getting 0.51

Answer 1

M1V1=M2V2

(1.50M)(85mL) = M2 (335)

M2 = 0.381

you have to take into account the volume of the total solution, 85+250 mL added to get a new molarity.