Predicting & Identifying Reactions & Products

Question 1

What are the group 1 elements known as?

Answer 1

alkali metals

Question 2

What are 3 properties of alkali metals?

Answer 2

soft
low density
low melting point
very reactive

Question 3

Why are alkali metals so reactive?

Answer 3

they have 1 electron in their outer shell which is really easy to lease, making it easier for them to reactive

Question 4

As you go down group 1, the elements:

Answer 4

get more reactive
have lower melting and boiling points

Question 5

Why are the lower alkali metals so reactive?

Answer 5

their valence shell is much further than the higher metals, meaning that their electron can be more easily lost.

Question 6

Alkali metal + water ➔

Answer 6

metal hydroxide + hydrogen

Question 7

What are the group 7 elements called?

Answer 7

halogens

Question 8

What are the group 0/8 elements called?

Answer 8

noble gases

Question 9

What do halogens exist as?

Answer 9

diatomic molecules

Question 10

As you go down group 7, the elements:

Answer 10

melting and boiling point increase
reactivity decreases

Question 11

Why are the lower halogens less reactive?

Answer 11

halogens need to attract electrons to achieve a full outer shell, but the lower halogens’ valence shell is further away and therefore has weaker forces of attraction

Question 12

What are halogen displacement reactions?

Answer 12

the more reactive halogen displaces the less reactive halogen

Question 13

Cl2 + 2KBr ➔

Answer 13

Br2 + 2KCl

Question 14

what is the main property of noble gases?

Answer 14

they are inert as they have full outer shells

Question 15

As you go down group 0, the elements:

Answer 15

boiling and melting points increase

Question 16

Fluorine is a _____ _____ coloured gas and is the _____ reactive halogen

Answer 16

poisonous, yellow, most

Question 17

Chlorine is a _____ coloured gas.

Answer 17

green

Question 18

Bromine is a _____-_____ _____ liquid which is also _____ .

Answer 18

red-brown, volatile, poisonous

Question 19

Iodine is a _____ coloured solid with _____ vapours.

Answer 19

grey, purple

Question 20

Are noble gases flammable?

Answer 20

no

Question 21

Sodium reacts with water to produce sodium hydroxide and a gas.
What is the name of the gas produced?

Answer 21

hydrogen

Question 22

What would happen if iron and lithium sulfate were mixed together?

Answer 22

nothing

Question 23

What is the order of the reactivity series?

Answer 23

potassium
sodium
lithium
calcium
magnesium
aluminium
carbon
zinc
iron
tin
lead
hydrogen
copper

Question 24

Do metals react more vigorously with acid or water?

Answer 24

acid

Question 25

What is the test for chlorine gas?

Answer 25

expose it to blue litmus paper, which will then turn red and bleach white if chlorine is present

Question 26

What safety precautions are required for testing chlorine gas?

Answer 26

wear a gas mask
do the experiment in a fume cupboard

Question 27

How do you test for oxygen gas?

Answer 27

expose it to a glowing splint, which will relight if oxygen is present

Question 28

How do you test for hydrogen gas?

Answer 28

expose it to a lit splint, which will create a squeaky pop if hydrogen is present

Question 29

How do you test for carbon dioxide gas?

Answer 29

bubble it through limewater, which will turn cloudy white if carbon dioxide is present

Question 30

How do you test for carbonate ions?

Answer 30

1) add dilute HCl to sample
2) bubble the produced gas through limewater
3) if limewater goes cloudy, CO2 was produced, therefore, carbonate ions are present

Question 31

How do you test for sulfate ions?

Answer 31

1) add dilute HCl to the sample
2) Add barium chloride solution
3) if white precipitate forms (Barium sulfate) sulfate ions are present

Question 32

Why do we add HCl to the sample when testing for sulfates?

Answer 32

to remove any carbonate or sulfite ions. These ions can react with barium ions to form a white precipitate giving us a false positive

Question 33

How do you test for halide ions?

Answer 33

1) add dilute nitric acid to sample
2) add silver nitrate
if chlorides are present, white precipitate is formed
if bromides are present, cream precipitate forms
if iodides are present, yellow precipitate forms

Question 34

Why do we add nitric acid to the sample when testing for halides?

Answer 34

to remove any carbonate or sulfite ions. These ions can react with silver ions to form a white precipitate giving us a false positive

Question 35

What are the 2 groups of tests for cations?

Answer 35

the flame tests
the metal hydroxide tests

Question 36

how do you conduct a flame test?

Answer 36

Take a nichrome wire loop, and clean it by dipping it in some dilute hydrochloric acid, rinsing it in distilled water, and then heating it over a Bunsen burner flame.
Dip the wire loop into the compound you want to test.
Hold the wire loop in the clear blue part of the Bunsen burner flame (this is the hottest part).
See what colour the flame turns as the compound burns.

Question 37

What are the flame colours for lithium, sodium, potassium, calcium, copper ions?

Answer 37

red, yellow, lilac, orange, green

Question 38

What is a limitation of the flame test?

Answer 38

if you have 2 or more different metals in your sample, then the colours of the flames will mix together, and you probably won’t be able to tell which metals you have.

Question 39

How do you conduct the metal hydroxide test?

Answer 39

react the cation with sodium hydroxide. The colour of the precipitate and solution tells us which cation is present

Question 40

What precipitates do copper (ll), Calcium, iron (ll), iron (lll), and zinc ions produce?

Answer 40

blue, white, green, brown, white

Question 41

How would you tell if calcium ions are present or zinc ions?

Answer 41

add excess NaOH until one of the solutions re-dissolves to form a colourless solution. The colourless solution has zinc ions