Unit 5 Questions

Question 1

How does reactivity vary across the s block?

Answer 1

It is highest at the bottom of group 1

Question 2

How does basic strength vary across the s block?

Answer 2

It is highest at the bottom of group 1

Question 3

What do all s block metals react with?

Answer 3

Acids (vigorously), oxygen, and burn in air

Question 4

How do s-block elements form oxides?

Answer 4

Group 1: 4M + O2 —> 2M2O
Group 2: 2M + O2 —> 2MO

Question 5

What happens if you add acid to an s-block oxide?

Answer 5

They are basic so you make salt and water

Question 6

What happens if an s-block metal reacts with water? How does this reaction vary through the groups?

Answer 6

It forms a hydroxide.

Group 1: The effervescence caused becomes increasingly more violent and from K onwards the hydrogen released can even ignite

Group 2: Be shows no reaction at all, Mg reacts only very slowly with water but well with steam. The rest are normal.

Question 7

Group 2 metal ions with OH- ions

Answer 7

Solubility increases

Question 8

Group 2 metal ions with CO3(2-) ions

Answer 8

They are all insoluble

Question 9

Group 2 metal ions with SO4(2-)

Answer 9

Solubility decreases

Question 10

Group 2 metals with nitrates

Answer 10

All soluble

Question 11

How can we differentiate between group 2 carbonates by heating?

Answer 11

The decompose into an oxide and CO2. As thermal stability increases down the group, the reaction slows down

Question 12

How can we differentiate between group 2 hydroxides by heating?

Answer 12

They decompose to form an oxide and water. As thermal stability increases down the group, the reaction becomes slower

Question 13

How does the solubility of group 2 hydroxides vary?

Answer 13

Increases down group

Question 14

How does the solubility of group 2 sulphites vary?

Answer 14

Decreases down group

Question 15

How does melting temperature vary among the halogens

Answer 15

It increases down the group

Question 16

What do halogens form halides with?

Answer 16

Metals. I realise that was a stupid question - I’m very sorry

Question 17

How does reactivity vary among the halogens?

Answer 17

It decreases down the group

Question 18

How do we carry out the white cream yellow precipitate test on halogens?

Answer 18

Add dilute aqueous nitric acid HNO3 followed by aqueous silver nitrate AgNO3

Question 19

How do we differentiate between the different silver nitrate precipitates?

Answer 19

Add ammonia. Silver chloride dissolves in dilute ammonia, silver bromide in concentrated ammonia, and silver iodide not at all.

Question 20

How do reactivity, oxidising power, and volatility vary amongst the halogens?

Answer 20

They decrease down the group

Question 21

What, when reacting with sodium metal, produces a bright orange flame and a white solid?

Answer 21

Any halogen

Question 22

What is observed when a halogen reacts with a sodium metal?

Answer 22

A bright orange flame and a white solid

Question 23

What does iron wool glow and burn in before making a brown gas?

Answer 23

Halogen vapour

Question 24

What happens if you put iron wool in halogen vapour? How does this vary amongst the halogens?

Answer 24

It glows and burns. This starts less readily further down the group.

Question 25

What colour change follows the reduction of permanganate?

Answer 25

Purple to almost colourless

Question 26

What colour change follows the reduction of dichromate?

Answer 26

Orange to green

Question 27

What colour change follows the reduction of iodine?

Answer 27

Brown to colourless

Question 28

What colour changes take place when aqueous S2O3(2-) is oxidised by aqueous I2, followed by the addition of starch?

Answer 28

Iodine colour fades to pale yellow. Starch turns mixture blue/black which is also decolourised

Question 29

What colour changes follow in the reaction between aqueous iodine and aqueous copper (II)?

Answer 29

The blue solution loses its colour. A white precipitate of CuI and a brown solution of I2 is formed

Question 30

What colour changes follow the reaction between aqueous manganate and aqueous Fe(2+) with excess aqueous H2SO4?

Answer 30

Turns pink

Question 31

How does the stability of different oxidation states vary across the p-block?

Answer 31

Lower oxidation states become more stable down the group

Question 32

What kind of pH does CO2 have?

Answer 32

It is acidic - makes a salt with an alkali

Question 33

Describe PbO (acidity, appearance) and the solubility of its salts

Answer 33

Orange amphoteric solid. Salts are insoluble unless you add nitric acid

Question 34

Describe the reactions of group IV chlorides with water

Answer 34

SiCl4 reacts quickly and violently CCl4 forms separate liquid layer (no access to Si’s D orbitals) PbCl2 does not react

Question 35

Name the only two soluble lead salts

Answer 35

Pb(NO3)2 and Pb(CH3COO)2

Question 36

Describe the appearance of Pb(OH)2

Answer 36

White precipitate

Question 37

Describe the appearance of [Pb(OH)4](2-)

Answer 37

Colourless solution

Question 38

Describe the appearance of PbCl2

Answer 38

White precipitate

Question 39

Describe the appearance of PbI2

Answer 39

BRIGHT YELLOW PRECIPITATE!!

Question 40

Describe the observations of Cl with H2SO4

Answer 40

HCl doesn’t react further - only white misty fumes

Question 41

Describe the observations of Br with H2SO4

Answer 41

Steamy fumes (HBr), orange fumes (Br2), and choking gas (SO2)

Question 42

Describe the observations of I with H2SO4

Answer 42

Steamy fumes (HI), purple fumes (I2), yellow solid (S), and rotten egg smell (H2S)

Question 43

What is the colour of [CoCl4] (2-)?

Answer 43

Blue

Question 44

What is the colour of [CuCl4] (2-)?

Answer 44

Yellow/green

Question 45

What is the colour of [Fe(H2O)6] (2+)?

Answer 45

Pale green

Question 46

What is the colour of [Fe(H2O)6] (3+)?

Answer 46

Yellow

Question 47

What is the colour of [Cr(H2O)6] (3+)?

Answer 47

Dark green

Question 48

What is the colour of [Co(H2O)6] (2+)?

Answer 48

Pink

Question 49

What is the colour of [Cu(H2O)6] (2+)?

Answer 49

Blue

Question 50

What is the colour of [Cu(NH3)4(H2O)2] (2+)?

Answer 50

Royal blue

Question 51

Dropwise and excess OH- with [Cr(H2O)6] (3+)

Answer 51

Grey-green ppt, ppt dissolves giving deep green solution

Question 52

Dropwise and excess OH- with [Fe(H2O)6] (2+)

Answer 52

Dark green ppt, no further reaction

Question 53

Dropwise and excess OH- with [Fe(H2O)6] (3+)

Answer 53

Red-brown ppt, no further reaction

Question 54

Dropwise and excess OH- with [Cu(H2O)6] (2+)

Answer 54

Pale blue ppt, no further reaction

Question 55

Give the formula for Kc

Answer 55

[C]^c [D]^d / [A]^a [B]^b

Question 56

Give the formula for Kp

Answer 56

P(C)^c P(D)^d / P(A)^a P(B)^b

Question 57

Which factors affect the values of Kp and Kc?

Answer 57

Only temperature