A 1.35 M NaCl solution has a density of 1.054g/mL at 20 degrees celcius.
How many grams of solvent are present in 650 mL of this solution.
I get a different answer than my teacher, here's what i did...
1. figure out the total mass of solution --> 1.054 g/mL x 650 mL = 685.1g
2. calculate moles NaCl = (Molarity) x (total volume) --> 1.35M x 0.650 L = 0.8775 mol
3. Mass NaCl = moles x mm --> mass NaCl =(0.8775mol) x (58.44g/mol) = 31.107g
4. Calculate mass solvent by subtracting total mass solution-mass solute(NaCl) --> Mass Solute = 685.1 g - 31.107 g = 653.99g
That was my answer, my teacher however got --> mass solvent = 685 - 51.3 g = 633.7g ( as his final step )
Any help would be awesome, thanks.