Classroom Chemistry- 3, 4 & 6

Question 1

You need to be able to label the diagram with solute, solvent and solutions.

Answer 1

Sugar is a solute. A solute is the substance that is dissolved in a solution ( usually the substance of smaller quantity )
Water is a solvent. A solvent is a substance that does the dissolving in a solution ( usually the substance of larger quantity )
Solution.

Question 2

Be able to define the following term. Suspension

Answer 2

A suspension will look cloudy because the solid has not completely dissolved in the water. Very small particles of a solid remain suspended without dissolving. If left the solid will eventually settle.

Question 3

Be able to define the following term. Solution.

Answer 3

A solution is made when solids dissolve in the liquid. The solute is uniformly distributed throughout the solvent. In water solutions, the water is the solvent and the solid that has dissolved is the solute.

Question 4

Be able to define the following term. Dissolving.

Answer 4

Dissolving is a process by which the particles of one substance becomes completely intermingled with those of another and remain that way indefinitely.

Question 5

Solution or suspension? Crushed candy and water.

Answer 5

Solution.

Question 6

Solution or suspension? Oil and water.

Answer 6

Suspension

Question 7

Solution or suspension? Molasses and water.

Answer 7

Solution.

Question 8

Solution or suspension? Corn starch and water.

Answer 8

Suspension.

Question 9

Solution or suspension? Sea salt and water.

Answer 9

Solution.

Question 10

Solution or suspension? Baking powder and water.

Answer 10

Suspension.

Question 11

Solution or suspension? Sand and water.

Answer 11

Neither.

Question 12

What are the three means of recovering a substance from a solution?

Answer 12

Evaporation, crystallization, and distillation.

Question 13

What are three means of recovering a substance from a suspension?

Answer 13

Decanting, buoyancy and filtering.

Question 14

Know the five steps and explain how Crystal forms out of salt dissolved in water when allowed to stand over a period of time.

Answer 14

By dissolving salt in boiling water we created a supersaturated solution. The modules in hot water move farther apart allowing more salt to be dissolved to fill the spaces. When the solution cools the liquid can hold less of the solute. So the excess particles have nowhere to go because molecules are closer together. These particles are deposited along the string sides of the cup or on the surface of the water in crystal form.

Question 15

Know four of six of the reasons why your crystal may not have formed.

Answer 15

Water not hot enough. Solution disturbed. Not enough salt. Wrong type of salt. Not stirred enough. Salt too old.

Question 16

What happened in the yeast experiment?

Answer 16

Since CO2 gas is heavier than air. The CO2 replaced the space in which there was O2. With the O2 unavailable the flame goes out. It is the chemical reaction of mixing solids and liquids that CO2 is produced ( yeast, sugar, warm water )

Question 17

What happened in the soda and salt experiment?

Answer 17

The salt reacts with the CO2 that is dissolved in the pop. Causing it to release CO2 gas from the liquid. CO2 gas fills the space in the balloon. Causing it to inflate.

Question 18

What happened in the vinegar and baking soda experiment?

Answer 18

When the vinegar. And the baking soda react together CO2 is released. Because CO2 is heavier than air. It pushes the air out of the soda bottle and fills the balloon