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question 35
as the concentration of solute in a solution becomes more concentrated:
a. the freezing point of the solution select an answer the freezing point of the pure solvent
b. the boiling point of the solution select an answer the boiling point of the pure solvent
c. the osmotic pressure select an answer pressure
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question 36
rank these substances or solutions by relative freezing point.

• highest freezing point a. pure h₂o
• second highest b. 0.60 m lino₃

medium c. 0.60 m ch₃oh
second lowest d. 0.60 m hcn
lowest freezing point e. 0.60 m ba(no₃)₂

Explanation:

Question 35

Step1: Analyze Freezing Point Depression

Freezing point depression: As solute concentration increases, the solution's freezing point is lower than the pure solvent's. So for part A, the relation is "is less than".

Step2: Analyze Boiling Point Elevation

Boiling point elevation: As solute concentration increases, the solution's boiling point is higher than the pure solvent's. So for part B, the relation is "is greater than".

Step3: Analyze Osmotic Pressure

Osmotic pressure ($\Pi = iMRT$): As solute concentration ($M$) increases, osmotic pressure increases. So for part C, the relation is "increases" (assuming the comparison is to a less concentrated solution, but contextually, as concentration rises, osmotic pressure is greater than before, so "is greater than" or "increases"—here, likely "increases" or "is greater than", but the dropdowns probably have options like "is less than", "is greater than", "increases". For osmotic pressure, as concentration becomes more concentrated, osmotic pressure increases (so relative to a less concentrated, it's greater). So part C: "increases" or "is greater than" (depending on options, but standard colligative properties: freezing point depression (solution < pure solvent), boiling point elevation (solution > pure solvent), osmotic pressure (higher concentration → higher osmotic pressure).

Freezing point depression depends on the number of solute particles (van't Hoff factor, $i$). Pure solvent has no solute, so highest freezing point. For solutions:

• Pure $\ce{H2O}$: highest (no solute, so $\Delta T_f = 0$).
• $\ce{CH3OH}$ (methanol): non - electrolyte, $i = 1$.
• $\ce{HCN}$: weak electrolyte, $i$ slightly > 1 (partial dissociation).
• $\ce{LiNO3}$: strong electrolyte, $i = 2$ (dissociates into $\ce{Li+}$ and $\ce{NO3-}$).
• $\ce{Ba(NO3)2}$: strong electrolyte, $i = 3$ (dissociates into $\ce{Ba^{2+}}$ and $2\ce{NO3-}$).

Freezing point depression: $\Delta T_f = iK_fm$. Higher $i$ (or more particles) → lower freezing point. So order from highest to lowest freezing point:

1. Pure $\ce{H2O}$ (a)
2. $0.60\ m\ \ce{CH3OH}$ (c, $i = 1$)
3. $0.60\ m\ \ce{HCN}$ (d, $i\approx1 - 2$)
4. $0.60\ m\ \ce{LiNO3}$ (b, $i = 2$)
5. $0.60\ m\ \ce{Ba(NO3)2}$ (e, $i = 3$)

Answer:

A. The freezing point of the solution is less than the freezing point of the pure solvent
B. The boiling point of the solution is greater than the boiling point of the pure solvent
C. The osmotic pressure increases (or "is greater than" if comparing to a less concentrated, but standardly, as concentration rises, osmotic pressure increases)

Question 36