Topic 3

Question 1

compound

Answer 1

A substance made of two or more elements chemically bonded together

Question 2

Mixture

Answer 2

Two or more chemical substances found together but not chemically bonded.

Question 3

element

Answer 3

A chemical substance that cannot be broken down into simpler substances. It is composed as one type of atom only.

Question 4

anhydrous

Answer 4

Salts that do not contain water of crystallisation often resulting from hydrated salts being heated.

Question 5

hydrocarbon

Answer 5

A compound made of hydrogen and carbon only.

Question 6

petroleum

Answer 6

The mixture of hydrocarbons found naturally formed by the decay of marine organisms. Also known as crude oil.

Question 7

Solvent

Answer 7

A liquid substance within which a solid can dissolve.

Question 8

solute

Answer 8

A soluble solid that has dissolved in a solvent.

Question 9

residue

Answer 9

The solution that passes through the filter in filtration.

Question 10

filtrate

Answer 10

The solution which passes through the filter during filtration.

Question 11

chromatography

Answer 11

A method used to separate and identify substances by dissolving them in a solvent and allowing them to be carried by the solvent through a sheet of filter paper. The dissolved solutes are deposited along the sheet of paper according to their solubility and mass.

Question 12

soluble

Answer 12

able to be dissolved

Question 13

Locating agent

Answer 13

A chemical substance that will react with the solute(s) separated in chromatography to produce a coloured substance. Locating agents are used to identify colourless compounds separated by chromatography.

Question 14

Rf equation

Answer 14

Rf=distance travelled by substance
———————————————-
distance travelled by solvent

Question 15

Fractional distillation

Answer 15

A chemical process that describes heating and separating substances by distillation into more useful products (or fractions) based on their boiling points. It is used in the refining of crude oil.

Question 16

filteration

Answer 16

A purification method used to remove an insoluble solid from liquids by pouring through a filter, such as filter paper.

Question 17

crystallisation

Answer 17

A purification method used to obtain solid dissolved in a solution. As the liquid part of the solution cools and becomes denser, there is less space for the solid particles to occupy. These particles are excluded from the liquid and form crystal arrangements on the side of the vessel containing them.

Question 18

Distillation

Answer 18

A purification method used to separate a mixture of liquids by boiling and condensing.

Question 19

simple distillation

Answer 19

used to obtain a solvent from a solution

Question 20

Carbonate test

Answer 20

Test - Add dilute acid
Result - carbon dioxide produced

Question 21

Chloride test

Answer 21

Test - acidify with dilute nitric acid, then add aqueous silver nitrate.
Result - white ppt (ppt - precipitate)

Question 22

Bromide test

Answer 22

Test - acidify with dilute nitric acid, then add aqueous silver nitrate.
Result - Cream ppt

Question 23

Iodide test

Answer 23

Test - acidify with dilute nitric acid, then add aqueous silver nitrate.
Result - yellow ppt

Question 24

Nitrate test

Answer 24

Test - Add aqueous sodium hydroxide then aluminium foil; warm carefully.
Result - Ammonia produced. turns damp red litmus paper blue.

Question 25

Sulfate test

Answer 25

Test - Acidify, then add aqueous barium nitrate or barium chloride. Result - white ppt.

Question 26

sulfite test

Answer 26

Test - Add dilute hyrdochloric acid, warm gently and test for the presence of sulfur dioxide. Result - Sulfur dioxide produced will turn acidified aqueous potassium manganate (VII) from purple to colourless.

Question 27

aluminium(Al3+)

Answer 27

Effect of aqueous sodium hydroxide - white precipitate, soluble in excess – gives a colourless solution Ionic equation - Al3+(aq)+3OH−(aq)→Al(OH)3(s)

Question 28

ammonium(NH4+)

Answer 28

Effect of aqueous sodium hydroxide - ammonia gas produced on heating. Turn red litmus blue. Ionic equation - NH4+(aq)+OH−(aq)→NH4OH(aq) NH4OH(aq)→NH3(g)+H2O(l)

Question 29

calcium(Ca2+)

Answer 29

Effect of aqueous sodium hydroxide - white precipitate, insoluble in excess Ionic equation - Ca2+(aq)+2OH−(aq)→Ca(OH)2(s)

Question 30

chromium(III)(Cr3+)

Answer 30

Effect of aqueous sodium hydroxide - green precipitate, soluble in excess – gives a green solution Ionic equation - Cr3+(aq)+3OH−(aq)→Cr(OH)3(s)

Question 31

copper(II)(Cu2+)

Answer 31

Effect of aqueous sodium hydroxide - light blue precipitate, insoluble in excess Ionic equation - Cu2+(aq)+2OH−(aq)→Cu(OH)2(s)

Question 32

iron(II)(Fe2+)

Answer 32

Effect of aqueous sodium hydroxide - green precipitate, insoluble in excess Ionic equation - Fe3+(aq)+3OH−(aq)→Fe(OH)3(s)

Question 33

zinc(II)(Zn2+)

Answer 33

Effect of aqueous sodium hydroxide - white precipitate, soluble in excess – gives a colourless solution Ionic equation - Zn2+(aq)+2OH−(aq)→Zn(OH)2(s)

Question 34

Ammonia gas test

Answer 34

Damp red litmus paper turns blue.

Question 35

Carbon dioxide gas test

Answer 35

Limewater turns milky

Question 36

Chlorine gas test

Answer 36

damp litmus paper bleaches white

Question 37

Hydrogen gas test

Answer 37

lighted splint ignites gas with a 'pop' sound

Question 38

Oxygen gas test

Answer 38

Glowing splint relights

Question 39

Sulfur dioxide

Answer 39

Turns acidified aqueous potassium manganate (VII) from purple to colourless.

Question 40

lithium, Li+

Answer 40

flame colour - red

Question 41

sodium, Na+

Answer 41

flame colour - yellow

Question 42

potassium, K+

Answer 42

flame colour - lilac

Question 43

copper(II), Cu2+

Answer 43

flame colour - blue-green

Question 44

barium, Ba2+

Answer 44

flame colour - green

Question 45

calcium, Ca2+

Answer 45

flame colour - orange-red