Hi I\'m struggling with my chemistry question here, Have 15 ml of 0.1 m KCl in t

Question

Hi I'm struggling with my chemistry question here, Have 15 ml of 0.1 m KCl in test tube, also this solutionfreezes at -3.00 C. molar mass of Kcl is 74.55 g/mol. I need to find m = moles solute/ kg solvent which is =(grams/molecular weight)solute / kg solvent. Doing by myself, I found my mass of solvent to be (0.015L) * (1000m/1L) * (1Kg/1000g) * (7455g/mL) =118.825kg. I'm stuck after this. Any help QQ? Hi I'm struggling with my chemistry question here, Have 15 ml of 0.1 m KCl in test tube, also this solutionfreezes at -3.00 C. molar mass of Kcl is 74.55 g/mol. I need to find m = moles solute/ kg solvent which is =(grams/molecular weight)solute / kg solvent. Doing by myself, I found my mass of solvent to be (0.015L) * (1000m/1L) * (1Kg/1000g) * (7455g/mL) =118.825kg. I'm stuck after this. Any help QQ?

Explanation / Answer

Water typically freezes at 0.0 degrees Celsius.
Therefore, your KCl solution that froze at -3.00 C would meana Tf of 3.
Tf=3 i=2 Kf=1.86
Tf=Kf x i x m
3=1.86 x 2 x m 3=3.72m 3/3.72=m m=0.806
0.806=moles of solute/kg of solvent
Assuming a density of 1.00g/ml, 15ml of KCl would be 0.201moles of KCl.
0.806=0.201/x x=0.25 kg of solvent
So, in an aqueous solution of 15ml KCl, you would have 250g ofwater.
I am not sure if I completely answered your question, becauseI was a bit confused as to what it was, so I just tried to solveeverything I could. I hope it helps!

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.