MDCAT Chemistry Formula & Reactions Sheet 2026

Chemistry is a memorisation-heavy paper but rewards pattern recognition. Memorise the formulas first, then build reaction maps.

Physical Chemistry Formulas

• PV = nRT
• Molarity = moles/volume(L)
• Molality = moles/kg of solvent
• pH = −log[H⁺]
• K_a × K_b = K_w (10⁻¹⁴)
• ΔG = ΔH − TΔS
• k = Ae^(−Ea/RT) (Arrhenius)
• Rate = k[A]^m[B]^n

Inorganic Highlights

• Periodic trends — atomic radius, IE, EA, EN
• s-block reactivity with water
• Transition metal coloured ions
• Halogen displacement series
• Common acids — HCl, H₂SO₄, HNO₃ properties

Organic Reactions Map

• Alkane → halogenation (UV light)
• Alkene → addition (HX, H₂O, Br₂)
• Alkyne → HgSO₄/H₂O → ketone
• Alcohol → oxidation: 1° → aldehyde → acid; 2° → ketone
• Aldehyde + Tollens → silver mirror
• Carboxylic acid + alcohol → ester (Fischer)
• Amine + HNO₂ — identification
• Benzene — nitration, sulphonation, FC alkylation/acylation

High-Yield Exceptions

• Markovnikov vs anti-Markovnikov (peroxide effect)
• Cannizzaro reaction — aldehydes without α-H
• Ortho/para vs meta directors
• Aromaticity — Hückel's rule (4n+2)

Markovnikov's Rule

In HX addition to alkenes, H goes to carbon with more H's.

FC Reaction

Friedel–Crafts alkylation/acylation of benzene with AlCl₃ catalyst.

Tollens Test

Ammoniacal silver nitrate — gives silver mirror with aldehydes.

Practice Plan

Memorise the formulas in week 1. Build reaction maps over weeks 2–4. Drill 50 MCQs daily from Premeth Chemistry MCQs.

FAQ

Q: How many reactions appear per UHS paper?

15–19 organic reactions on average (UHS 2020–2024).

Q: Periodic table allowed in exam?

No — you must memorise atomic numbers up to Z=36.

Q: Hardest organic chapter?

Carbonyl compounds — 5–6 MCQs every year.

Q: How to revise daily?

10-minute reaction recall + 30 MCQs — non-negotiable.

Q: Best textbook for Chemistry?

Punjab textbook for theory; FBISE for clarity. PMDC matches both.

Use this alongside the Physics formula sheet and Biology MCQs.