P Block Elements (Grp - 16)

Question 1

O
S
Se
Te
Po

Down the grp

Answer 1

size ↑

Ionisation Potential ↓
EN ↓

Electron affinity ↓*
[S > Se > Te > O]
O is small and has more e⁻ - e⁻ repulsion

Question 2

Barytes

Answer 2

BaSO₄

Question 3

Galena

Answer 3

PbS

Question 3

Epsom salts

Answer 3

MgSO₄.7H₂O

Question 3

Cinnabar

Answer 3

HgS

Question 4

Zinc Blends

Answer 4

ZnS

Question 5

Pitch Blend

Answer 5

Ore of U
Contains some Po

Question 6

H₂O
H₂S
H₂Se
H₂Te

Down the grp

Answer 6

E-H bond length ↑
E-H bond energy ↓
Reduction power ↑
Acidity ↑
Thermal stability ↓

Question 7

EO₃

Answer 7

E = S, Se, Te

SO₃ - Acidic
SeO₃ - Acidic
TeO₃ - Acidic

Question 7

EO₂

Answer 7

E = O, Se, S,Te

O₃ - neutral
SO₂ - acidic
SeO₂ - Amphoteric
TeO₂ - Amphoteric

Question 7

MP & BP

Answer 7

H₂S < H₂Se < H₂Te < H₂O

H₂O has H- bonding

Question 8

Ag + O₃

Answer 8

Ag + O₃ → Ag₂O + O₂

Question 8

E + Halogen

Answer 8

EX, EX₂ , EX₄ & EX₆
EX₆ only for SF₆ - due to octahedral

SF - gas
SeF₄ - liquid
TeF₄ - gas
down the grp M.M increases

SeX - not possible
exist as dimes Se₂X₂

Se₂Cl₂ →SeCl₄ + Se

Question 8

KClO₃ / Δ →
AgO₂ / Δ →

Answer 8

KClO₃ / Δ → KCl + O₂
AgO₂ / Δ → Ag + O₂

Manufacture of O₂

Question 9

I⁻ + O₃ + H₂O

Answer 9

I⁻ + O₃ + H₂O → I + OH⁻

Used to estimate O₃

Question 9

Nature of Oxides

Answer 9

Grp 1 - Basic

Grp 2 - basic except BeO (Ampho)

Grp 13 -
B₂O₃ - Acidic
₂O₃ - Ampho
₂O₃ - Ampho
₂O₃ - Basic
₂O₃ - Basic

Grp 14 , 15 & 16 - refer notes

Grp 17 - acidic

Mixed and sub oxide - refer notes

Question 9

O₂ + silent electric discharge / ozonizer

Answer 9

3O₂ ⇄ 2O₃

ΔH = -ve (Endo)
ΔS = -ve (3 molecule - 2 molecule = randomness decreases)

ΔG = +ve for all temp. (ΔG = ΔH - TΔS)

Question 10

Hg + O₃

Answer 10

Hg + O₃→ HgO₂ + O₂

tailing of Mercury

Question 11

Rhombic Sulphur

Answer 11

α - Sulphur

Roll-S + CS₂ / Δ → S₈ (Rhombic)

Question 12

Monoclinic sulphur

Answer 12

β - Sulphur

S₈ (Rhombic) + 365K ⇄ S₈ (Monoclinic/crown)

Question 13

Eangel Sulphur

Answer 13

S₆ - Chair form

Question 14

Contact process

Answer 14

Manufacture of H₂SO₄

S + O₂ →SO₂

SO₂ + O₂ in V₂O₅ / 450°C ⇄ SO₃

SO₃ + H₂SO₄(old acid) → H₂S₂O₇

H₂S₂O₇ + H₂O → H₂SO₄

Question 15

Oxidation of S

Answer 15

Refer notes

Question 16

S as Ox. , Red. Agent

Answer 16

Refer notes

Question 17

Oxoacids of Sulhur

Answer 17

Refer notes

Question 18

Bleaching Agent

Answer 18

SO₂ + H₂O H₂SO₃ → [H] (nascent hydrogen)

Colored molecule + [H] → Reduce form (colorless)