Mixtures (Yr_7)

Question 1

What is a pure substance?

Answer 1

There are two types of pure substances. THere is an element, which is where every atom within the substance is the same and the compound which is where two substances are chemicall ybonded together.

Question 2

What is the difference between a compound pure substance and a mixture?

Answer 2

Compound pure substances are chemically bonded while mixtures aren’t and can be separated without a chemical process.

Question 3

What is a solution?

Answer 3

Solutions contain tiny particles that are too small to be seen even by a microscope, for example, sugar in water. They are always transparent but can be various colours.

Question 4

What is a suspension?

Answer 4

Suspensions happen when a solid is mixed with a liquid and it doesn’t dissolve. If it is let undisturbed, the solid will eventually settle at the bottom as sediment.

Question 5

What is a colloid?

Answer 5

Colloids are pretty much suspensions except for that the fact that nothing settles down at the bottom as sediment. They typically loom cloudy.

Question 6

What is an emulsion?

Answer 6

Emulsions are colloids made of two or more liquids, but unlike suspensions, when left alone, tiny drops of the emulsion will float to the top. This can be stopped by adding emulsifiers which completely mix the liquids.

Question 7

What is the difference between a solute and a solvent?

Answer 7

The solute is the thing dissolved and the solvent is the thing that dissolves. For example, sugar is the solute and water is the solvent.

Question 8

What is the difference between soluble and insoluble?

Answer 8

When a substance is able to be dissolved, it is called soluble, but when it isn’t, it is called insoluble.

Question 9

What is concentration?

Answer 9

Concentration is how much solute is in the solute.

Question 10

What is the difference between dilute and saturated?

Answer 10

Dilute means there is a low concentration while concentration means that there is a high concentration.

Question 11

What is saturated?

Answer 11

Saturated means that no more solute can be dissolved into a solution.

Question 12

What is decantation?

Answer 12

Decantation is when you pour liquid away to leave sediment in the container.

Question 13

What is sedimentation?

Answer 13

Sedimentation is when a mixture is left alone so that the particles settle at the bottom as sediment.

Question 14

What is flotation?

Answer 14

Flotation is letting the particles float to the top of the mixture.

Question 15

What is centrifuging?

Answer 15

Centrifuging is when a mixture is spun which separates the light and heavy particles.

Question 16

What is filtration?

Answer 16

Filtration is using a filter to separate insoluble liquids from a liquid. This works because a filter has hole which allows certain things to pass through.

Question 17

What is evaporation and crystallisation?

Answer 17

Evaporation is when you use heat to remove liquid and allow the solid to remain, the solid will form gradually with the help of crystallisation.

Question 18

What is distillation?

Answer 18

Distillation is an extension of evaporation which happens by adding in condensation. Distillation collects the evaporated substance and waits for it to cool down and collects the liquid.

Question 19

What is chromatography?

Answer 19

Chromatography is a separation technique used to separate mixtures with very similar properties. It works because different substances in a mixture flow at different speeds. The dried paper is called a chromatogram.