A water solution containing an unknown quantity of a nonelectrolyte solute is found to have a freezing point of -0.23°C. What is the molal concentration of the solution?
2.1 m
8.1 m
0.12 m
0.43 m

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.

i think it's letter a.