CH combines process calculations, transport, thermodynamics, reaction engineering, process control and chemical technology. Mathematics is part of the tested syllabus, not an optional supplement.

Chemical Engineering is tested within a 100-mark paper. The paper also includes General Aptitude. The sections below show the complete subject syllabus.

GATE CH Syllabus and Marks Distribution

There is no optional subject block in this paper. All listed sections are part of the syllabus.

Chemical Engineering Unit-wise Syllabus

Engineering Mathematics

• Linear Algebra: Matrix algebra; Systems of linear equations; Eigenvalues and eigenvectors.
• Calculus: Functions of single variable; Limit, continuity and differentiability; Taylor series; Mean value theorem; Evaluation of definite and improper integrals; Partial derivatives; Total derivative; Maxima and minima; Gradient, divergence, and curl; Vector identities; Directional derivatives; Line, surface, and volume integrals; Stokes, Gauss, and Green’s theorems.
• Differential Equations: First order equations (linear and nonlinear); Higher order linear differential equations with constant coefficients; Cauchy’s and Euler’s equations; Initial and boundary value problems; Laplace transforms; Solutions of one-dimensional heat equation, wave equation, and Laplace equation.
• Complex Variables: Complex number; polar form of complex number.
• Probability and Statistics: Definitions of probability and sampling theorems; Conditional probability; Mean, median, mode, and standard deviation; Random variables; Poisson, Normal, and Binomial distributions.
• Fundamentals of AI/ML: Linear Regression; Principal Component Analysis (PCA).
• Numerical Methods: Numerical solutions of linear and non-linear algebraic equations; Integration by trapezoidal and Simpson’s rule; Single and multi-step methods for numerical solution of ordinary differential equations; Finite-difference method for partial differential equations.

Process Calculations

• Steady and unsteady state mass and energy balances including multiphase, multi -component, reacting and non-reacting systems; Use of tie components; Recycle, bypass and purge calculations; Gibbs phase rule and degree of freedom analysis.

Thermodynamics

• Laws of thermodynamics; Open and closed systems; Entropy and chemical potential; Thermodynamic properties of pure substances: equations of state and residual properties; Thermodynamic properties of mixtures: partial molar properties, fugacity, excess properties, and activity coefficients; Phase equilibria: predicting VLE of systems; Chemical reaction equilibrium.

Fluid Mechanics and Mechanical Operations

• Newtonian and non-Newtonian fluids; Fluid statics; Surface Tension; Fluid kinematics; Equation of continuity, Equation of motion, Equation of mechanical energy; Macroscopic friction factors; Dimensional analysis and similitude; Inviscid flows: Euler equation; Flow through pipes: velocity profile, pressure drop, Bernoulli equation, flow meters; Pumps; Turbulent flow: fluctuating velocity, universal velocity profile, pressure drop; Elementary boundary layer theory; Flow past immersed bodies including packed and fluidized beds.
• Particle size and shape; Particle size distribution; Size reduction and classification of solid particles; Free and hindered settling; Centrifuge and cyclones; Thickening and clarification; Filtration, agitation and mixing.

Heat Transfer

• Equation of energy; Steady and unsteady heat conduction, convection, and radiation; Thermal boundary layer and heat transfer coefficients; Boiling, condensation, and evaporation; Types of heat exchangers and evaporators and their process calculations; Design of double pipe, shell and tube heat exchangers, and single and multiple effect evaporators.

Mass Transfer

• Fick’s laws; Molecular diffusion in fluids; Mass transfer coefficients; Film, penetration and surface renewal theories; Momentum, heat and mass transfer analogies; Stage-wise and continuous contacting and stage efficiencies; HTU & NTU concepts.
• Fundamentals concepts and design of mass transfer operations: distillation, absorption, leaching, liquid-liquid extraction, drying, humidification, dehumidification and adsorption, membrane separations.

Chemical Reaction Engineering

• Theories of reaction rates; Kinetics of homogeneous reactions; Interpretation of kinetic data; Single and multiple reactions in ideal reactors; Kinetics of enzyme reactions (Michaelis-Menten and Monod models); Non-ideal reactors: residence time distribution, single parameter model; Non-isothermal reactors; Kinetics of heterogeneous catalytic reactions; Diffusion effects in catalysis; Catalyst deactivation.

Instrumentation and Process Control

• Measurement of process variables; Sensors and transducers; P&ID equipment symbols; Process modeling and linearization; State-space models; Transfer functions and dynamic responses of various systems; Systems with inverse response; Process reaction curve; Controller modes (P, PI, and PID); Control valves; Analysis of closed loop systems including stability, frequency response, controller tuning, cascade and feed forward control.

Plant Design and Economics

• Principles of process economics and cost estimation including depreciation and total annualized cost, cost indices, rate of return, payback period, discounted cash flow; Optimization in process design and sizing of chemical engineering equipment such as heat exchangers and multistage contactors; Batch plant scheduling.

Chemical Technology

• Overview of raw materials, unit operations, and processes involved in inorganic chemical industries (synthesis gas, sulfuric acid, phosphoric acid, chlor-alkali industry), fertilizers (ammonia, urea), natural products industries (pulp and paper, sugar and ethanol), petroleum refining and petrochemicals (ethyl benzene, styrene, ethylene oxide), polymerization industries (polyethylene and polyester).

General Aptitude Syllabus

General Aptitude contributes 15 marks within the 100-mark paper. It is not an additional paper that can be left out when choosing the technical sections.

Chapter-wise Weightage and Important Topics

Only the section-wise marks are fixed. IIT Madras has not assigned a guaranteed number of marks to each chapter of Chemical Engineering. A topic may appear in one year and receive fewer questions in another; a past-paper count is not an official 2027 weightage.

For a chapter-weightage comparison, record the year, paper code, session, question number and marks of each matching question. Keep a combined question under one main topic or label the overlap explicitly; counting it twice inflates the total. GATE previous-year question papers can be used for this topic-by-topic practice.

Question Types and Negative Marking

The paper uses one-mark and two-mark questions. The number of MCQ, MSQ and NAT questions is not a fixed chapter-wise quota. In an MSQ, selecting one correct option is not enough when the correct answer contains two options.