Question

You begin pouring sodium chloride into a glass of water. For a long time, the sodium chloride just dissolves in the water, but suddenly it begins to pile up at the bottom of the glass. Which statement is true?
oA. The sodium chloride has increased the temperature of the water.
oB. The sodium chloride has decreased the temperature of the water.
oC. The water is unsaturated.
oD. The water is saturated.

Answer 1

Answer:

• Option D: The water is saturated

Explanation:

Solubility is the term used to designate the maximum amount of a solute that can be dissolved in a given amount of solvent, at a given temperature and pressure.

At start, you begin with pure water in the glass. This water is a pure substance, not a solution.

When you begin pouring sodium chloride into the glass of water, a solution, i.e. a homogenous mixture of solute and solvent, is formed.

This solution, at first, is diuted, which means that it contanins just few grams (matter) of the solute dissolved.

As, more sodium chloride is dissolved, the solution becomes more concentrated but is unsaturated. At some point, the water cannot dissolve more sodium chloride, because it has reached the maximum amount that can contain at that temperature and pressure. Then, the solution is saturated.

You can tell that the water is saturated, ie it contaiins the maximum amount of sodium chloride that can be dissolved, by that amount of water, at the given temperature, because from that point, you will note that as you pour more sodium chloride, it begins to pile up at the bottom of the glass. Hence, the true statement is the letter D: the water is saturated.