Chapter 12

Question 1

What is a pure substance?

Answer 1

a substance that only contains 1 element or a compound

Question 2

What is an impure substance?

Answer 2

a substance that can be a mixtures of elements, mixtures of compounds, or mixtures of elements and compounds

Question 3

What is 1 thing that impurities can affect?

Answer 3

the boiling point

Question 4

What is a formulation?

Answer 4

substances that don’t react with one another

Question 5

What is the equation for an Rf value?

Answer 5

Rf = distance moved by the compound / distance moved by the solvent

Question 6

How do you test for the presence of hydrogen?

Answer 6

a lighted wood splint makes a popping sound in a test tube of hydrogen

Question 7

How do you test for the presence of oxygen?

Answer 7

a glowing wooden splint relights in a test tube of oxygen

Question 8

How do you test for the presence of carbon dioxide?

Answer 8

bubble the gas through limewater, the carbon dioxide turns the water cloudy

Question 9

How do you test for the presence of chlorine?

Answer 9

it has a characteristic, choking smell. It also makes blue litmus paper turn red, and then it bleaches white. It also makes damp starch-iodide paper turn blue/black