Dynamic Equilibrium and System Properties

1. Dynamic Equilibrium (⇄): This is a dynamic, not static, state. Temperature relates to the speed of molecules. Concentration formulas include C = n/v, n = C * v, and v = n/C.

• Rate: The rate of the forward reaction equals the rate of the reverse reaction.
• Concentration: Concentrations remain constant at equilibrium, though they are not necessarily equal.
• Molecules: Molecules are destroyed and created at the same speed.
• System Type: Must be a closed system where no matter flows in or out. It requires constant temperature (no phase change, color change, or pressure change).

Inert Gases and Catalysts

• Inert Gases: Adding an inert gas (e.g., Ar, He) results in no shift in equilibrium.
• Catalysts: Adding a catalyst

Acid-Base Equilibrium Practice Problems

1. The conjugate acid of HAsO₄²⁻ is:
   Answer: C. H₂AsO₄⁻
2. Which of the following tests could be used to distinguish between 1.0 M HCl and 1.0 M NaOH?
   Answer: C. II and III only
3. Consider the following Brønsted-Lowry equilibrium:
   C₆H₅NH₂(aq) + H₂O(l) ⇌ C₆H₅NH₃⁺(aq) + OH⁻(aq)
   The substances acting as acids and bases from left to right are:
   Answer: C. Base, acid, acid, base
4. Which of the following are amphiprotic?
   I. H₂O, II. NH₄⁺, III. HCO₃⁻
   Answer: B. I and III only
5. Which of the following represents the equilibrium expression for the ionization of water?
   Answer: A.
6. Which of the following will have the lowest electrical conductivity?
   Answer: D. 1.00 M H₃PO₄
7. Water acts as an acid when

80 Essential English Irregular Verbs

Verb Conjugations: Past Simple and Past Participle

• 1. Be: was/were, been
• 2. Beat: beat, beaten
• 3. Become: became, become
• 4. Begin: began, begun
• 5. Bet: bet, bet
• 6. Break: broke, broken
• 7. Bring: brought, brought
• 8. Broadcast: broadcast, broadcast
• 9. Build: built, built
• 10. Buy: bought, bought
• 11. Catch: caught, caught
• 12. Choose: chose, chosen
• 13. Come: came, come
• 14. Cost: cost, cost
• 15. Cut: cut, cut
• 16. Do: did, done
• 17. Draw: drew, drawn
• 18. Drink: drank, drunk
• 19. Drive: drove, driven
• 20. Eat: ate, eaten
• 21. Fall: fell, fallen
• 22. Feed: fed, fed
• 23. Feel: felt, felt
• 24. Fight: fought, fought
• 25. Find: found, found
• 26. Fly: flew, flown
• 27. Forget: forgot, forgotten
• 28. Get: got, got
• 29. Give: gave, given
• 30. Go: went, gone
• 31. Grow:

Shear Stress in Beams

• 16.1 Rectangular beam: b = 100 mm, d = 250 mm, L = 3 m, w = 40 kN/m → Find τmax + distribution
• 16.2 Triangular section: b = 100 mm, h = 150 mm, F = 13.5 kN → Find τmax + distribution
• 16.3 Circular section: d = 100 mm, F = 30 kN → Find τmax + distribution
• 16.4 I-section: Flange = 150×20 mm, Web = 300×10 mm, F = 50 kN → Find τmax
• 16.5 I-section: D = 350 mm, B = 200 mm, web = 12.5 mm, flange = 25 mm, F = 200 kN → Shear stress distribution
• 16.6 T-section: F = 100 kN, I = 113.4 × 10⁶ mm⁴ → Shear at points + distribution
• 16.7 Unequal I-section: σc = 17.5 MPa, F = 100 kN → Bending moment + shear distribution
• 16.8 Irregular section: F = 20 kN → Shear at points + distribution
• 16.9 Square (diagonal): Diagonal

Pulmonary Ventilation and Gas Exchange

Pulmonary ventilation: This is the mechanism through which the air in the lungs and the respiratory tract is renewed. It allows air to flow in and out of the lungs. Ventilation is carried out through two respiratory movements: inhalation and exhalation. The diaphragm and the intercostal muscles mainly participate in these movements. By contracting and relaxing, these muscles produce changes in the volume of the lungs.

Inhalation

This is the movement that allows air to enter the lungs.

1. The diaphragm contracts, increasing the vertical diameter of the thoracic cavity.
2. The external intercostal muscles contract. The diameters of the thoracic cavity increase.
3. The lungs, which are elastic, expand.

Exhalation

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1. जनसंचार माध्यम क्या हैं?

उत्तर: वे माध्यम जिनके द्वारा सूचना, समाचार और विचार एक साथ बहुत से लोगों तक पहुँचते हैं, उन्हें जनसंचार माध्यम कहते हैं।

उदाहरण: अख़बार, रेडियो, टेलीविज़न, इंटरनेट आदि।

2. जनसंचार माध्यम के प्रकार

उत्तर: जनसंचार माध्यम मुख्यतः दो प्रकार के होते हैं:

• प्रिंट मीडिया: जैसे

Food and Meals Vocabulary

Food Categories

• Dairy products: butter, cream, semi-skimmed milk
• Fruit: avocado, cherry, peach, plum
• Meat, fish, and seafood: cod, lamb, prawn, tuna, turkey
• Sweets and bakery products: muffin, pancake, pie
• Vegetables: sweetcorn, olive, carrot, lettuce, pea
• Others: oil, rice

Meals

• canteen
• dessert
• dish
• fast food
• main course
• packed lunch
• school meal
• starter
• vending machine
• snack

Describing Food

• baked
• boiled
• fattening
• fresh
• fried
• juicy
• salty
• spicy
• stale (rancio)
• tasty
• fresh
• processed
• raw
• fried
• frozen
• roast
• rotten (podrido)

Education and Study Vocabulary

Study Subjects

• architecture
• art
• biology
• business studies
• chemistry
• citizenship
• computing
• design and technology
• drama
• engineering
• English
• geography
• history
• law
• literature
• marketing
• maths
• music
• philosophy
• media studies
• medicine
• politics

Key Concepts of Human Migration

Migration: Migration refers to the movement of people from one place to another, usually across a political or geographical boundary. It can be internal or international.

Immigration: This is the process of entering a country to live there permanently or for a long period of time.

Net Migration Rate: This measures the difference between the number of people entering and the number of people leaving (emigrants).

• Formula: Net Migration Rate = (Immigrants - Emigrants) per 1,000 people.
• If the number is positive, the population increases; if it is negative, people are leaving.

Natural Growth: This refers only to the change caused by births and deaths.

• Formula: Natural Growth = Births - Deaths.
• If births exceed deaths = Positive

🔹 Isomerism (Class 11)

Definition:

Isomers are compounds having the same molecular formula but a different arrangement of atoms or different spatial arrangement, resulting in different properties.

1️⃣ Structural Isomerism

(Atoms have a different connection)

(A) Chain Isomerism

Definition:

Same molecular formula but a different carbon chain (straight or branched).

Example:

• C₄H₁₀
  • n-Butane → CH₃–CH₂–CH₂–CH₃
  • Isobutane → CH₃–CH(CH₃)–CH₃
• C₅H₁₂
  • Pentane
  • Isopentane
  • Neopentane

(B) Position Isomerism

Definition:

Same carbon chain and functional group, but the position of the functional group or multiple bond is different.

Example:

• C₃H₈O
  • 1-Propanol (–OH on C-1)
  • 2-Propanol (–OH on C-2)
• C₄H₈
  • 1-Butene
  • 2-Butene

(C) Functional

Biology Fundamentals

Genetics: DNA and RNA

• DNA: Double helix structure; carries genetic information. Bases pair A–T and C–G.
• RNA: Single strand; uses Uracil (U) instead of Thymine (T); assists in protein synthesis.

Cell Division

• Mitosis: Results in two identical daughter cells; essential for growth and repair.
• Meiosis: Results in four genetically different cells; produces gametes (sperm and egg).

Chromosomes

• Humans possess 23 pairs, totaling 46 chromosomes:
  • 22 pairs are autosomes.
  • 1 pair consists of sex chromosomes (X/Y).
• Sex determination: Males are XY; Females are XX.

Inheritance Principles

• Dominant Allele: Expressed even if only one copy is present.
• Recessive Allele: Expressed only when two copies are present.
• Use Punnett squares to predict trait outcomes