C2 - Experimental techniques

Question 1

Which piece of equipment is used to measure time and what is the unit? [2]

Answer 1

• Stopwatch
• Seconds

Question 2

What piece of equipment is used to measure temperature and what is the unit? [2]

Answer 2

• Thermometer
• Degrees in celsius

Question 3

What piece of equipment is used to measure mass and what is the unit? [2]

Answer 3

• Mass balance
• Grams

Question 4

Which pieces of equipment are used to measure volume of a liquid and what is the unit? [4]

Answer 4

• Measuring cylinder
• Volumetric pipette
• Burette
• Cm³

Question 5

What piece of equipment is used to measure volume of a gas and what is the unit? [2]

Answer 5

• Gas syringe
• Cm³

Question 6

What process is used to separate two or more solids that are soluble? [1]

Answer 6

• Paper chromatography

Question 7

How do you calculate Rf values in paper chromatography? [1]

Answer 7

• Distance moved by solute divided by distance moved by solvent

Question 8

Define a pure substance [1]

Answer 8

• A substance that contains a single element of compound not mixed with any other substance

Question 9

Describe 3 ways the purity of a substance can be assessed [3]

Answer 9

• Melting point
• Boiling point
• Chromatography

Question 10

Describe how melting/boiling point can be used to assess purity [2]

Answer 10

• A pure substance will have a sharp melting/boiling
• An impure substance will melt over a temperature range

Question 11

Describe how chromatography can be used to assess purity [1]

Answer 11

• A pure substance will produce only one distinct spot on a chromatogram

Question 12

Give two examples of purity of a substance being important [3]

Answer 12

• Manufacture of products used in;
  + Drugs
  + Food additives

Question 13

What is a solvent? [1]

Answer 13

• A substance that dissolves a solute

Question 14

What is a solute? [1]

Answer 14

• A substance dissolved in a solvent

Question 15

What is a solution? [1]

Answer 15

• A liquid mixture composed of two or more substances

Question 16

Define volatility [1]

Answer 16

• How easily a substance evaporates

Question 17

Define solubility [1]

Answer 17

• How easily a substance dissolves

Question 18

What is filtration used for? [1]

Answer 18

• To separate an insoluble solid from a liquid

Question 19

What is the filtrate in filtration? [1]

Answer 19

• The liquid or solution that has passed through the filter

Question 20

What is crystallisation? [1]

Answer 20

• When a liquid containing dissolved salt is evaporated, leaving the salt behind

Question 21

What is distillation used for? [1]

Answer 21

• Separating a solvent from a solution

Question 22

What is the difference between immiscible liquids and miscible liquids? [2]

Answer 22

• Immiscible liquids don’t mix
• Miscible liquids mix

Question 23

How can immiscible liquids be separated? [1]

Answer 23

• By the use of a separating funnel

Question 24

Why can fractional distillation be used to separate miscible liquids and gases? [1]

Answer 24

• Because different liquids and gases have different boiling points

Question 25

What is a residue? [1]

Answer 25

• A substance that remains after distillation, evaporation, filtration or similar process