Our Sun will eventually turn into a red giant and, finally, a white dwarf. Use the Hertzsprung-Russell diagram to describe how the Sun's luminosity and temperature will change as it goes through these
stages.

The Hertzsprung-Russell diagram let me see that the sun will be more luminous and less hotter when it turns into a red giant. When the sun turns into a white dwarf it will be more hotter and less luminous.

nacl is added to the aqueous of what? ? in order to get a proper answer you have to specify the exact composition of the aqueous solution.