Which of the following is the EXACT (non-approximated) mathematical formula for the relative lowerin — Solutions and Colligative Properties Chemistry Question

💡 Solution & Explanation

The standard formula is $\frac{P^0_A - P_s}{P^0_A} = \frac{n_B}{n_A + n_B}$. Taking the reciprocal gives $\frac{P^0_A}{P^0_A - P_s} = \frac{n_A + n_B}{n_B} = \frac{n_A}{n_B} + 1$. Subtracting 1 gives $\frac{P^0_A - P^0_A + P_s}{P^0_A - P_s}$ which simplifies exactly to $\frac{P_s}{P^0_A - P_s} = \frac{n_A}{n_B}$. Inverting again yields the powerful exact formula: $\frac{P^0_A - P_s}{P_s} = \frac{n_B}{n_A}$.