Classification of Matter (Lesson 2)

Question 1

Pure Substance

Answer 1

• Made up only one atom/molecule bonded together
• Has constant composition
• CANNOT be separated physically or chemically

Question 2

Mixture

Answer 2

• Made up or more than 2 or more pure substances that are physically combined
• Has variable composition
• Chemical bonds are neither broken or formed

Question 3

Homogenous Mixture

Answer 3

• Solution
• Has a uniform composition/appearance
• Components are evenly distributed within

Question 4

Ways to separate mixture components

Answer 4

-Distillation
-Filtration
-Centrifugation
-Chromatography
-

Question 5

Under what circumstances does distillation work best?

Answer 5

• Dependant on component volatility differences

- Best for separating liquid from a solid in homogenous mixture & a solution of 2 liquids with far boiling points

Question 6

How does Distillation work?

Answer 6

Mixture is heated until the most volatile component vaporizes; the vapour passes through a cooled tube, changes state, and condenses back in to liquid state.

Question 7

What is Filtration?

Answer 7

• Separation of a solid from liquid in heterogeneous mixture

- Can be used with gravity or sped up with partial vacuum

Question 8

How does Filtration Work?

Answer 8

Mixture is poured on filter paper in a funnel, liquid passes through and solid is left behind

Question 9

What the difference with filtering water vs distilling it?

Answer 9

• In distillation, toxic chemicals like chlorine and pesticides (have a lower boiling point than water) are often carried over and become very concentrated in the final product.
• Distilled water is very acidic and lacks healthy minerals.
• Filtered water allows the healthy minerals to exist in final product and still removes harmful substances.

Question 10

What is Centrifugation?

Answer 10

-The process of separation insoluble materials from liquid in a heterogenous mixture when particles are too small to be filtered

− Based on
− Size, shape, and density of particles
− Viscosity of medium
− rotation speed

Question 11

How does Centrifugation work?

Answer 11

Centrifuge has rotor (holds the centrifuge tubes). The rotor holds tubes of equal amounts of solid-liquid mixture. When rotor rapidly rotates, the tubes horizontally rotate because of centrifugal force. Therefore, the insoluble denser particles separate from liquid. End, the solid particles end up at bottom of centrifuge

(Centrifuge rapidly spins mixtures to create a centripetal force that causes the denser material to settle at the bottom and the less dense material to move to the top)

Question 12

What is Chromatography

Answer 12

• the separation of a homogenous mixture using a stationary phase and a mobile phase because of the mixture’s components different affinities for the mobile phase
• Stationary phase is solid and mobile phase is gas/liquid

Question 13

How does Chromatography work?

Answer 13

• A porous paper strip (filter paper) is used for stationary phase.
• A drop of mixture placed on strip. The strip is dipped in liquid (mobile phase) that travels up the paper.

Question 14

Heterogenous Mixture

Answer 14

• Has variable composition

- Different mixture components can be distinguished

Question 15

Heterogenous Mixture

Answer 15

• Has a non-uniform composition/appearance
• Made up of different substances that remain physically separate
• EX: blood

Question 16

What is distillation?

Answer 16

• the process of separating a liquid from a solid in a homogenous mixture
• also the process of separating 2 liquids with far boiling points