A mother finds her daughter’s mug of hot cocoa on a table an hour after she had been

Question

drinking it. As the mother pours out the cocoa, she sees brown solids in the bottom of the
mug. How can this be explained? (1 point)
The cocoa was mixed with hot water, but some cocoa settled as it cooled because the solubility
went up.
The cocoa was mixed with hot water, but some cocoa settled as it cooled because the solubility
went down.
All dissolved substances will come out of solution over time. If the mother waits long enough,
then all of the powder will appear at the bottom of the mug.
This would only happen if too much cocoa powder was added in the first place, because the
solubility should not change.

Answer 1

The best explanation for the observation that the mother found brown solids in the bottom of the mug after the cocoa had cooled is: The cocoa was mixed with hot water, but some cocoa settled as it cooled because the solubility went down.

When hot cocoa is prepared, cocoa powder dissolves more easily in hot water due to its higher solubility at elevated temperatures. However, as the cocoa cools, the solubility of cocoa in water decreases, leading to some of the dissolved cocoa becoming less soluble and precipitating out as solid particles. This explains the brown solids at the bottom of the mug.