Colloids and interfaces in the environment

Question 1

What are the 3 phases of matter?

Answer 1

Solid (definite shape and volume)
Liquid (take container shape, fixed volume)
Gases (shape and volume of container)

Question 2

What 2 things can happen to substances when transitioning between phases?

Answer 2

Increased temp- faster particle, pushed apart
Attractive force- stickiness, pull together

Question 3

What is a colloid?

Answer 3

Mixture of 2 phases of matter

Question 4

What are some examples of colloids?

Answer 4

Liquid aerosols
Solid aerosols
Liquid foam
Emulsions
SOL (solid liquid)
Solid foam
Gel
Solid sol

Question 5

What is a SOL? (colloid)

Answer 5

solid particles dispersed in a liquid

Question 6

What are some examples of SOLs? (colloid)

Answer 6

Paint
Starch
Tea in water
Soapy water

Question 7

What is a gel or solid emulsion?

Answer 7

continuous network of solid particles dispersed in liquid (e.g., jellies)

Question 8

How will colloidal solutions appear?

Answer 8

milky

Question 9

What is the particle diameter range in colloids?

Answer 9

1-1000nm

Question 10

What does not happen with colloid particles?

Answer 10

don’t settle to bottom of container and cannot be removed by filtering

Question 11

What is the Tyndall effect?

Answer 11

a way to distinguish a colloid from solution by shining a light through as the large particles in the colloid will scatter light

Question 12

What other particles are around the size of colloids?

Answer 12

Smaller then bacterium
Larger then protein
Around size of virus

Question 13

What does PM stand for?

Answer 13

particulate matter

Question 14

What are the 3 main types of pm size?

Answer 14

10
2.5
0.1

Question 15

What is the most dangerous type of pm?

Answer 15

0.1 as ultrafine and can make it to alveoli and into bloodstream while 10 only trachea and 2.5 bronchioles

Question 16

How can soils be colloids?

Answer 16

pore in between soil particles fill with water in sand there is bigger void while clay is more platy

Question 17

What properties can vary between soils?

Answer 17

swelling
shrinkage
and contribution to aggregate stability

Question 18

What will tend to organic compounds in soil because of their large surface area?

Answer 18

will usually sorb onto or into soil colloids

Question 19

In what industries are colloids used?

Answer 19

Effluent treatment (flocculant)
Paint industry
Food
Cosmetics and toiletries
Detergent industry
Pharmaceutical industry
Agriculture

Question 20

What is a micelle?

Answer 20

Particle of colloidal dimensions that exists in equilibrium with the molecules or ions in solution which it formed

Question 21

What are micelle polymers like?

Answer 21

Organized self-assembly formed in a liquid
and composed of amphiphilic macromolecules, made of
hydrophilic (like water) and hydrophobic (hate water) blocks

Question 22

What is the reason why water isnt at gas at current earth temp and atmospheric pressure?

Answer 22

due to H bonds

Question 23

Why dont water and oil mix?

Answer 23

oil is hydrogen and carbon little unpaired to interact with water

Question 24

How can oil and water be forced to mix?

Answer 24

by adding energy e.g, stirring
but re-separation will occur

Question 25

When can be added to oil and water to form a bridge between the 2?

Answer 25

Surface active molecule or surfactant

Question 26

What does a surfactant do?

Answer 26

sit on the interface of oil and water and stabilises the mixture

Question 27

What can surfactants be used to remediate?

Answer 27

oil spills by pulling oil down into water

Question 28

What are the positives of using surfactants for oil spills?

Answer 28

oil broken down into smaller blobs which are more available to micro organisms

Question 29

What problem can arise from using surfactants?

Answer 29

they are a chemical which alter surface tension and waters H bond

Question 30

What can affect the effectiveness of using surfactants on oil spills?

Answer 30

Viscosity (thickness) of the oil
Wind speed
Wave height & frequency
Interferes with other methods