Unit Test1 AY25 G7 IGCSE

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

• adding more solute.

• adding ice.

• heating the solvent.

• removing some solvent.

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

• diluted

• unsaturated

• saturated

• supersaturated

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 in contact with water.

• It has the smallest surface area in contact with water

• It has the largest number of sugar molecules.

• It has the fewest bonds between sugar modules.

Based on the given solubility curve, how many grams of sugar will dissolve in a 50 mL of water at 20°C?

• 100 g

• 150 g

• 200 g

• 250 g

Which substance is MOST soluble at 90 ºC?

• Solid A

• Solid B

• Solid C

• All are equally soluble

Observe the given solubility curve. If 50 grams of potassium chloride is dissolved in 100 grams of water at 50ºC, the solution can be described as ___________

• supersaturated

• saturated

• unsaturated

• dilute

Which of the following factors affect the rate of dissolving?

• Size of the solute particles, stirring, and temperature

• Size of the solvent particles, stirring, and temperature

• Size of the solute particles, mixing, and pressure

• Size of the solvent particles, mixing, and pressure

Here is chromatography of markers with the paper placed in water. What is true?

• Blue dissolves best in water.

• Yellow dissolves best in water.

• Green dissolves best in water.

• Pink dissolves best in water

In the image, which dye is the most soluble?

• red

• blue

• purple

• all are equally soluble

Which two were the same mixture of dyes?

• 1 and 5

• 2 and 6

• 3 and 4

• 4 and 6