1 What is 1st ionization energy? Give an example.
2 Factors responsible for increasing reactivity of alkali metals down the group?
3 Give reason for different chemical reactivities of Na and Mg toward oxygen and chlorine.
4 Why elements of group 13 and 17 called P–Block elements?
5 Predict how bond angle in H₂S would be different from that in H₂O?
6 What is bond order?
7 Explain the difference between formation of σ and π bonds.
8 What is molar volume of a gas? How Avogadro’s number is related with molar volume?
9 39g potassium and 56g iron have equal number of atoms. Justify.
10 Differentiate theoretical and actual yields. How is percentage yield calculated?
11 What is limiting reactant? How does it control the quantity of product?
12 How is concept of mole derived from Avogadro’s number?
13 Why does wood burn more rapidly in pure oxygen than in air?
14 Difference between enthalpy change of reaction and energy of activation.
15 A catalyst lowers the activation energy – illustrate.
16 ‘I₃⁻’ of Mg is much bigger than its ‘I₂⁻’. Justify.
17 State Moseley’s law. Give mathematical formula.
18 Explain Hund’s rule. Give an example.
19 Boiling point of water different at Lahore and Murree hills. Why?
20 What is polarizability? Relation with London dispersion forces.
21 Earthenware vessels keep water cool. Justify.
22 What is habit of a crystal? Give an example.
23 Mention the characteristics of chemical equilibrium.
24 Why ice at 0 °C can be melted by applying pressure without supply of heat?
25 Differentiate between macroscopic and microscopic events in a chemical equilibrium.
26 Major difference between homogeneous and heterogeneous equilibrium with example.
27 How and why electrical double layer is formed?
28 Calculate OX. No. of chromium (Cr) in Cr₂(SO₄)₃.
29 What is a disproportionation reaction?
30 What is meant by standard electrode potential (E₀)?
31 Enthalpy of a system – what do you understand?
32 Define standard enthalpy of atomization and give one example.
33 Define lattice energy. How it is affected?
34 Give energy profile diagrams for endothermic and exothermic reactions.
35 Bond dissociation energy – meaning and expression.
36 Two differences between cyclopentane and pentane.
37 Explain why alkanes have high stability.
38 Why order of stability of carbocation is 3° > 2° > 1°?
39 How Markovnikov’s rule is applied in addition of HBr to 2-pentene.
40 How elimination reaction is considered the opposite of an addition reaction?
41 How can deforestation impact air quality?
42 How does polycyclic aromatic hydrocarbon (PAHs) affect human health?
43 How do volatile organic compounds (VOCs) affect air quality?
44 Why carbon monoxide is called silent killer?
45 What is meant by low altitude ozone?
46 Why does common ion effect decrease solubility of less soluble salt?
47 N₂ is least reactive. Justify.
48 Why sulphur show variable oxidation state like +2, +4, and +6?
49 Define common ion effect with example.
50 Pure water is poor conductor of heat and electricity. Justify.
51 How sulphur used in gunpowder?
52 F₂ is more reactive than other halogens. Why?
53 Why Cl₂ is more volatile than Br₂ and I₂?
54 Why HF is weaker acid than HCl?
55 How Cl₂ perform disinfection activity?
56 Role of London dispersion forces in trend of volatility.
57 Write down reaction of redox for catalytic converter.
58 How NH₃ can be prepared by ammonium salt in laboratory?
59 Define solubility product constant Ksp with example.
60 Differentiate between acidic and basic buffer.