Question

which would have a higher boiling point?
2.0 m nano₃
1.5 m alcl₃
the boiling point is the same for both solutions.
which would have a higher osmotic pressure?
2.0 m nano₃
1.5 m alcl₃
the osmotic pressure is the same for both solutions.

Explanation:

Step1: Determine van't Hoff factors

For $NaNO_3$, it dissociates into $Na^+$ and $NO_3^-$, so $i = 2$. For $AlCl_3$, it dissociates into $Al^{3 +}$ and $3Cl^-$, so $i=4$.

Step2: Calculate effective particle concentrations for boiling - point elevation

The boiling - point elevation formula is $\Delta T_b=K_bmi$, where $m$ is molality (assume same as molarity for dilute solutions here). For $2.0\ M\ NaNO_3$, the effective particle concentration is $2.0\ M\times2 = 4.0\ M$. For $1.5\ M\ AlCl_3$, the effective particle concentration is $1.5\ M\times4=6.0\ M$. Since a higher effective particle concentration leads to a higher boiling - point elevation, $1.5\ M\ AlCl_3$ has a higher boiling point.

Step3: Calculate effective particle concentrations for osmotic pressure

The osmotic pressure formula is $\Pi = iMRT$. For $2.0\ M\ NaNO_3$, the effective particle concentration is $2.0\ M\times2 = 4.0\ M$. For $1.5\ M\ AlCl_3$, the effective particle concentration is $1.5\ M\times4 = 6.0\ M$. Since osmotic pressure is directly proportional to the effective particle concentration, $1.5\ M\ AlCl_3$ has a higher osmotic pressure.

Answer:

1. 1.5 M AlCl₃
2. 1.5 M AlCl₃