Sugar and Salt solutions are:

Question

Which one of the following is not correct for an ideal solution?

Answer 1

Stir sugar into a glass of water and compare it with a glass of milk and a glass of muddy water.

Heterogeneous mixtures: muddy water looks patchy and uneven while it is settling, but sugar water looks the same all the way through, so it is not like a heterogeneous mixture.
True solutions: once the sugar disappears completely into the water, leaving it clear and uniform with nothing left to see or settle, that is the behavior of a true solution, and both sugar water and salt water match it.
Colloidal solutions: milk stays cloudy and scatters light because of its dispersed fat particles, but dissolved sugar water is clear, not cloudy, so it does not behave like milk.
Suspensions: muddy water eventually settles into layers, but sugar water never does, since there is nothing left undissolved to settle.

Sugar and salt solutions behave like nothing but a true solution, clear and permanently uniform, so that is the correct answer.

Answer 2

Apply three checks to sugar and salt solutions: do they dissolve completely, do they stay clear, and do they ever settle?

Heterogeneous mixtures: these fail the clarity and uniformity check, since a heterogeneous mixture shows visibly different regions, unlike a dissolved sugar or salt solution.
True solutions: sugar and salt pass all three checks: they dissolve fully, stay perfectly clear, and never settle, which defines a true solution.
Colloidal solutions: these fail the clarity check, since colloids scatter light and look at least somewhat cloudy, unlike a clear sugar or salt solution.
Suspensions: these fail the dissolving check, since a suspension's particles never dissolve and eventually settle, unlike sugar or salt once dissolved.

Sugar and salt solutions pass every check for a true solution, so that is the correct answer.

Answer 3

Apply three checks to sugar and salt solutions: do they dissolve completely, do they stay clear, and do they ever settle?

Heterogeneous mixtures: these fail the clarity and uniformity check, since a heterogeneous mixture shows visibly different regions, unlike a dissolved sugar or salt solution.
True solutions: sugar and salt pass all three checks: they dissolve fully, stay perfectly clear, and never settle, which defines a true solution.
Colloidal solutions: these fail the clarity check, since colloids scatter light and look at least somewhat cloudy, unlike a clear sugar or salt solution.
Suspensions: these fail the dissolving check, since a suspension's particles never dissolve and eventually settle, unlike sugar or salt once dissolved.

Sugar and salt solutions pass every check for a true solution, so that is the correct answer.

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