which of these is a possible freezing point for a 1.0 m solution of kno₃ in water? the normal freezing point…

Explanation:

Step1: Recall Freezing Point Depression

Freezing point depression is a colligative property: adding a solute (like ( \text{KNO}_3 )) to a solvent (water) lowers the solvent’s freezing point. The formula is ( \Delta T_f = i \cdot K_f \cdot m ), where ( i ) is the van’t Hoff factor, ( K_f ) for water is ( 1.86^\circ\text{C·kg/mol} ), and ( m ) is molality (≈ molarity for dilute solutions).

Step2: Analyze ( \text{KNO}_3 ) Dissociation

( \text{KNO}_3 ) dissociates into ( \text{K}^+ ) and ( \text{NO}_3^- ), so ( i \approx 2 ). For ( 1.0 , \text{M} ) (≈ ( 1.0 , \text{m} )) solution:
( \Delta T_f = 2 \cdot 1.86^\circ\text{C·kg/mol} \cdot 1.0 , \text{mol/kg} \approx 3.72^\circ\text{C} )? Wait, no—wait, the options have ( -0.6^\circ\text{C} ). Wait, maybe approximate ( i ) or consider molarity vs. molality, but the key is freezing point decreases (below ( 0.0^\circ\text{C} )). So the freezing point should be ( 0.0^\circ\text{C} - \Delta T_f ), so negative. Among options, only ( -0.6^\circ\text{C} ) is below ( 0 ).

Answer:

(-0.6 , ^\circ\text{C}) (the option with (-0.6 , ^\circ\text{C}))