10 Chemical analysis

Question 1

In chemistry, what is a pure substance?

Answer 1

something made of only one type of substance

Question 2

What is the difference between the melting and boiling points of a pure and impure substance?

Answer 2

pure - sharp/one specific temperature

impure - broad/occurs across a range of temperatures

Question 3

What is a formulation?

Answer 3

a mixture designed for a specific purpose

Question 4

What are some examples of formulations?

Answer 4

fuels, cleaning agents, paints, medicines, alloys, fertilisers, and foods

Question 5

What is chromatography?

Answer 5

a process for separating coloured mixtures

Question 6

How is Rf calculated?
(Written as: Capital R, subscript f)

Answer 6

Rf =

distance moved by substance
/
distance moved by solvent

Question 7

What is the test for hydrogen?

Answer 7

a lit splint gives squeaky pop

Question 8

What is the test for oxygen?

Answer 8

re-lights a glowing splint

Question 9

What is the test for carbon dioxide?

Answer 9

turns limewater milky if bubbled through it

Question 10

What is the test for chlorine?

Answer 10

bleaches damp litmus paper