Solutions Vocabulary

In chemistry, a "mole" is:

• The mass of an atom
• a large number used to count particles
• based on the volume of a substance

What is the molar mass of NaCl?

• 58.45g/mol
• 28g/mol
• 12g/mol
• 6.02 x 10²³

How do we get mass from moles?

• multiply by avogadro's number
• multiply by molar mass
• divide by avogadro's number
• divide by molar mass

Which would NOT increase the rate at which a sugar cube dissolves?

• Reducing the amount of solvent

• Crushing the sugar cube

• Stirring the solution

• Heating the solvent

Tags

NGSS.MS-PS1-4

You can make a solute dissolve more quickly in a solvent by

• adding more solute.

• adding ice.

• heating the solvent.

• removing some solvent.

Tags

NGSS.HS-PS1-5

A solution that contains all of the solute it can hold at a given temperature is

• diluted.

• saturated.

• supersaturated.

• unsaturated.

The amount of solute that can be dissolved in a specific amount of solvent at a given temperature is its

• concentration.

• density.

• dilution.

• solubility.

Three 10 g samples of sugar are represented below.

Sample A dissolves in water more slowly than sample B.

Sample B dissolves more slowly than sample C.

Which of the following best explains why sample A dissolves more slowly than the other two?

• It has the most volume.

• It has the smallest surface area.

• It has the largest number of sugar molecules.

• It has the fewest bonds between sugar modules.

Tags

NGSS.HS-PS1-3

A student pours mineral salts into a bottle of cold water. Which of the following best explains why shaking the bottle will affect the dissolving rate of the salt?

• Shaking exposes the salts to the solvent more quickly.

• Shaking helps more water evaporate.

• Shaking equalizes the water temperature.

• Shaking causes more ions to precipitate out of solution.

A technican prepared a solution by heating 100 mL of distilled water while adding KCl crystals until no more KCl would dissolve. She then capped the clear solution and set it aside on the lab counter. After several hours she noticed the solution had become cloudly and some solid had settled to the bottom of the flask. Which statement best describes what happened?

• As the solution cooled, evaporation of water increased the KCl concentration beyond its solubility.

• Water molecules, trapped with the KCl crystals, were released after heating.

• At lower temperatures the solubility of KCl decreased and recrystallization occurred.

• At increased temperatures the solubility of KCl increased and remained too high after cooling.

Tags

NGSS.HS-PS1-5