What is the percent by volume of isopropyl alcohol in a solution made
by dissolving 18.9 mL of isopropyl
alcohol in 412 mL of water?

Explanation:

V%=( V of solute ÷ V of solution ) ×100%

    = ( 18.9          ÷  (18.9  + 412) ) ×  100%

   =  4.38%

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.