How many moles of ions would you expect in an aqueous solution containing one mole of chromium(III) chloride? Hint: write out the dissociation equation for chromium(III) chloride to determine how many ions are present.

Four  

Explanation:

AlCl₃(aq) ⟶ Al³⁺(aq) + 3Cl⁻(aq)

One mole of AlCl₃  produces 1 mol of Al³⁺ and 3 mol of Cl⁻.

That's four moles of ions.

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.