A10-kg mass of a 50 w/w percent ethanol-water solution is heated from 60 of to a temperature at which half of the original mixture has vapourized (on a mass basis). assume that the vapour formed remains in contact with the liquid remaining. [10 marks] (a) (b) (c) to what temperature is the mixture heated? [4 marks] what is the composition of the vapour formed? [3 marks] how much heat is added?

n has four pairs of electrons in the valence shell, electrons repel one another ,n has 7 protons in its nucleus, and since n has 7 protons, it must fill the second shell, giving it 4 pairs of electrons. the electrons form 3 bonds and 1 lone pair of electrons. each pair of electrons repels the other pairs, so they are equally far apart.

so all of the above

increased stability in the completion of fluorine's outer shell.

po-215 i got it right on the quiz

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.