practice questions (all topics)

Question 1

what is a mixture?

Answer 1

two or more compounds or elements that are physically bonded (not chemically)

Question 2

what are miscible liquids?

Answer 2

miscible liquids are ones that can mix together – like water and ethanol

Question 3

what are immiscible liquids?

Answer 3

immiscible liquids are ones that can’t mix together - like oil and water

Question 4

why are alloys harder than metals?

Answer 4

they are made of atoms of different sizes, rather than being uniform (disrupted layers), meaning layers of atoms cannot slide over eachother easily, which makes the whole alloy stronger than any pure metal

Question 5

why does copper conduct electricity?

Answer 5

it has a large number of delocalised electrons that are free to move, therefore can carry electric charge

Question 6

what separating technique is used to separate ethanol from ethanol and water?

Answer 6

fractional distillation

Question 7

what separating technique is used to separate salt from sea water?

Answer 7

filtration

Question 8

what separating technique is used to separate different colours in black ink?

Answer 8

chromatography

Question 9

what is the formula for the retention factor value?

Answer 9

RF= distance travelled by spot/distance travelled by solvent