Solutions Review

The rate of dissolving will speed up by doing all of the following EXCEPT...

• stirring the solution

• breaking up a solid solute

• decreasing the temperature

• increasing the temperature

Substances can be divided into pure substances and mixtures.

Which of the following is a mixture?

• gold

• air

• water

• aluminum

Two students were doing an experiment which involved adding potassium sulfate powder to water. They added one teaspoon of potassium sulfate to water and stirred it, and all the powder dissolved. They continued to do this until, after the fourth teaspoon, no more potassium sulfate would dissolve.

As more potassium sulfate dissolves in the water, the mixture becomes...

• more concentrated

• less concentrated

• dilute

• more cloudy

Jack and Jill were conducting solubility experiments using sucrose (sugar) and water. They began with room temperature water (22^oC) and then heated the water to boiling. They calculated the amount of sugar that could be dissolved in the water as the temperature increased. Jack and Jill lost their data and were trying to graph their results from memory. Help them out! Which graph is the MOST reasonable representation of their expected data?

• Graph A

• Graph B

• Graph C

• Graph D

Tags

NGSS.MS-PS1-4

Maddie wanted to make a sugar-water solution to put in her hummingbird feeder. She found some sugar cubes and was about to drop them into a glass of water, when her brother suggested crushing the cubes before mixing. Was this a good suggestion? Why or why not?

• No, crushed or cubed does not matter.

• Yes, crushing the cube results in more sugar in the water.

• Yes, crushing the sugar cube provides more contact between the sugar and water.

• No, the particle size does not matter as long as she stirs the mixture of sugar and water.

Tags

NGSS.MS-PS1-2

If two unidentified solids of the same texture and color have different solubilities in 100 grams of water at 20°C, you could conclude that

• They are the same substane

• They are different substances

• They have different melting points

• Their solubilities will be the same if the temperature increases

If you have 140 grams of potassium nitrate (KNO₃) in a solution at 50°C, in terms of saturation, how would you classify this solution?

• saturated

• unsaturated

• supersaturated

• There is not enough information to answer this question

Tags

NGSS.MS-PS3-4

Based on the solubility chart, which of the listed salts below is the most soluble at 25 ^oC?

• sodium nitrate

• sodium chloride

• potassium nitrate

• potassium chlorate

If 180 grams of potassium iodide is dissolved in 100 cm³ of water at 30^oC, a(n) _______________ solution is formed.

• saturated

• unsaturated

• oversaturated

• supersaturated

Tags

NGSS.MS-PS1-4

160 grams of sodium nitrate is dissolved in 100 cm³ of water at 90^oC. When the solution cools to 60^oC, some of the salt settles out in the bottom of the beaker. The salt settles out because the solution is now...

• saturated

• unsaturated

• oversaturated

• supersaturated

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4