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Flashcards in C1c Deck (23)
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1
Q

What is a solution?

A

-mixture of solute and solvent that does not separate

2
Q

What is a solvent?

A

-liquid a solute is dissolved into

3
Q

What is a solute?

A

-a substance being dissolved

4
Q

What does insoluble mean?

A

-will not dissolve

5
Q

What does soluble mean?

A

-will disolve

6
Q

What does solubility mean?

A

-measure of how much will dissolve

7
Q

Why is nail vanish insoluble in water?

A
  • the attraction between nail polish molecules to each other is stronger than its attraction to water molecules
  • the attraction between water molecules to each other is stronger than its attraction to nail polish molecules
  • more attracted to themselves than each other, and don’t form a solution
8
Q

Why is nail vanish soluble in acetone?

A

-the attractions between acetone molecules(nail polish remover) and nail polish molecules is stronger than the attractions holding the substances together

9
Q

What do paints contain?

A
  • pigment to give colour
  • binding medium: carries pigment bits and holds them together, when it goes solid it stick the pigment to the painted on surface
  • solvent: thins the paint and makes it easier to spread
10
Q

What are colloids?

A
  • tiny particles of one substance dispersed into another substance
  • mixed but not dissolved
11
Q

Why do colloids not separate?

A
  • the particles are too small

- they don’t settle out at the bottom

12
Q

How do water-based (emulsion) paints dry?

A
  • solvent used is water
  • binding medium usually an acrylic or vinyl acetate polymer
  • solvent evaporates, leaving the binder and pigment
  • a thin layer dries quite quickly
  • ideal for inside walls
13
Q

How do oil-based paints dry?

A

-solvent:organic compound that dissolves oil
-binding medium is oil
1-solvent evaporates
2-the oil is oxidised by the air before it turns solid
-ideal for outside doors and metalwork

14
Q

What are the advantages and disadvantages of oil paints?

A
  • advantages:glossy, waterproof, hard-wearing

- disadvantages: solvents used often produce harmful fumes

15
Q

What are the advantages of water-based paints?

A

-fast-drying, no harmful fumes

16
Q

What are thermochromic pigments?

A
  • pigments that change colour or become transparent when heated or cooled
  • different pigments change colour at different temperatures
  • a mixture of pigments can be used to make a colour-coded temperature scale, which are used to make basic thermometers that stick to your head and take temperature
17
Q

What are some uses for thermochromic pigments?

A
  • electric kettles that change colour as water boils
  • baby products, e.g. bath toys and baby spoons, often have them added as a safety feature
  • drink mugs to tell if drink it too hot
  • mood rings
18
Q

What happens if you mix thermochromic pigments with paint?

A
  • mix with acrylic paint to give a wide range of colour changes
  • e.g. blue thermochromic pigment loses colour at 27C, , with a yellow acrylic paint would give a paint that’s green below 27C and yellow above 27C
  • the blue pigment has become transparent
19
Q

How do phosphorescent pigments work?

A
  • absorb natural or artificial light and store energy in their molecules.
  • energy is released as light over a period of time
20
Q

What did people use to paint glow-in-the-dark watches and what was wrong with it?

A
  • radioactive paints
  • they would glow for years without being needed ‘charging’ by putting them in light
  • they were not safe and could give quite a dose of atomic radiation
21
Q

What are some uses of thermochromic pigments mixed with paint?

A

-these are also used in novelty mugs, designed to change colour when a hot drink is poured inside or become transparent and reveal a picture

22
Q

What does solubility depend on?

A

-the solvent used

23
Q

What are some uses of phosphorescent pigment?

A
  • watches and clocks with glow-in-the-dark hands
  • traffic lights
  • toys
  • novelty decorations
  • emergency exit signs