NEET UG medical entrance exam Chemistry syllabus, question papers, notes, online practice tests, MCQ questions and Chemistry previous year papers. Rate of a reaction (Average and instantaneous), factors affecting rate of reaction: concentration, temperature, catalyst; order and molecularity of a reaction, rate law and specific rate constant,integrated rate equations and half life (only for zero and first order reactions), concept of collision theory (elementary idea, no mathematical treatment). Activation energy, Arrhenious equation.