What do FE Chemical practice problems actually look like?

Multiple choice, four options, usually phrased 'most nearly', and the options sit close enough that you cannot eliminate them by inspection — on this exam, sometimes within a percentage point of each other. Many carry a figure: a process flow sketch, a stress element, a concentration profile, a sieve curve. NCEES gives 110 questions in a 6-hour appointment, of which 5 hours 20 minutes is exam time, so the working time per question is under three minutes once you allow for reading, a handbook lookup and a check.

What is on the FE Chemical exam that is not on any other FE exam?

Four subjects. Mass Transfer and Separation at 8-12 questions, Chemical Reaction Engineering at 7-11, Process Design at 7-11, and Solids Handling at 3-5. Searching every other FE specification — area names and subtopics alike — none of the five other FE exams mentions mass transfer, separation, reaction engineering, reaction kinetics, process design or solids handling anywhere. Together those four areas carry 25 to 39 of the 110 questions. Note that Material/Energy Balances, despite being the largest area here, is not in that list: two other FE exams cover mass and energy balances as a subtopic.

How many questions are on each FE Chemical topic?

Material/Energy Balances is the largest at 10-15. Fluid Mechanics/Dynamics, Thermodynamics, Heat Transfer, and Mass Transfer and Separation follow at 8-12 each; Chemistry and Biology, Chemical Reaction Engineering, and Process Design at 7-11 each; Mathematics 6-9; Safety, Health and Environment 5-8; Probability and Statistics, Engineering Sciences, Materials Science, Economics and Process Control 4-6 each; Solids Handling and Ethics and Professional Practice 3-5 each. That is 17 knowledge areas, more than FE Civil, Mechanical or Other Disciplines carry, and the ranges sum to between 100 and 153 against an exam of 110.

Is FE Chemical harder than the other FE exams?

Different rather than harder, and the difference is specialisation rather than difficulty. No single area dominates — the largest is under 10% of the paper, the same as on FE Civil and FE Mechanical — but a quarter to a third of the questions come from subjects a candidate can only have met on a chemical engineering degree. Whether that makes it harder depends entirely on what you studied.

What reference material do you get on the FE Chemical exam?

The exam is closed book with an electronic reference: the NCEES FE Reference Handbook is supplied on-screen as a searchable PDF, and no personal copies or outside material are allowed. Practise with the searchable PDF rather than a printed copy — with 17 knowledge areas to move between, finding the right page quickly is a substantial part of the skill being tested.

FE Chemical practice problems: the specialist FE exam

Four subjects on this paper appear on no other FE exam anywhere: mass transfer and separation, chemical reaction engineering, process design, and solids handling. Between them they are 25 to 39 of the 110 questions. Here are three real problems, worked in full — including one whose wrong answer sits six-tenths of a percentage point from the right one.

Updated August 31, 2026 · by the FE to PE Prep team

110

Questions

5h 20m

Exam time

Knowledge areas

25–39

ChemE-only areas

The arithmetic is easy. The bookkeeping is not.

Each of the three problems below is a two-line calculation. None of them needs calculus, none needs an iteration, and the handbook prints every formula involved. They are still hard, and they are hard in a way that practising more algebra will not fix.

The wrong answers are usually other real quantities from the same problem. In the evaporator question, the tempting distractor is the concentrate flow — a number you genuinely have to compute on the way to the answer. Nothing about writing it down feels like an error.
The difficulty is deciding what to compute, not how. Mass transfer is driven by a difference in concentration, not a concentration; a mass balance asks for one stream out of three. Getting those right is comprehension, and comprehension is what a three-minute clock attacks.
One dropped term can move the answer by less than a percent. The overshoot problem below has a distractor 0.6 points from the truth. There is no order-of-magnitude glance that saves you, and both numbers are on the page.
Seventeen knowledge areas means seventeen places in the handbook. That is more than FE Civil, FE Mechanical or FE Other Disciplines carry, and searching well is a bigger share of the skill here than on any depth-heavy exam.

Three real problems

One from Material and Energy Balances, the largest area on the exam; one from Mass Transfer, which exists on no other FE paper; and one from Process Control. All three are drawn from our free FE Chemical set. Try each before opening the solution, and read the distractor notes.

1. Evaporation rate from a mass balance

Material and Energy Balances is the largest area on this exam at 10–15 questions, and this is its archetype. Two balances, one subtraction, no calculus. The whole difficulty is knowing which number the question asked for.

1
medium
A. Steady-state material balances
A feed of 1000 kg/h containing 12 wt% solute is concentrated in an evaporator. Pure water leaves overhead as vapor V and a concentrated liquid leaves at 40 wt% solute. The water evaporation rate V is most nearly:
1. 700 kg/h
2. 300 kg/h
3. 880 kg/h
4. 120 kg/h
Show the answer & worked solution
Answer: A.700 kg/h
Solute balance: L = F·w_F/w_L = 1000·0.12/0.4 = 300 kg/h; overall balance: V = F − L = 700 kg/h. Distractors: the CONCENTRATE L reported instead of the evaporated water, 300; ALL the feed except the entering solute assumed to evaporate (product's retained water ignored), F·(1 − w_F) = 880; and the SOLUTE THROUGHPUT F·w_F reported, not the water removed, 120.

What the distractors teach: Every wrong answer is a real stream from the same correctly-solved problem. 300 kg/h is the concentrate leaving the bottom — a number you must compute on the way to the answer, which makes it the easiest thing in the world to write down. 120 kg/h is the solute throughput. 880 kg/h is what you get assuming everything except the entering solute evaporates, forgetting that the product stream carries water out with it. Three plausible flows, all of them belonging to this evaporator, and only one of them is the vapour.

2. Molar flux through a stagnant film

Mass Transfer and Separation carries 8–12 questions, and no other FE exam mentions the subject at all. Fick's first law is one division. What is being tested is whether you know what the driving force is.

2
medium
A. Molecular & convective diffusion
Species A diffuses at steady state through a stagnant film of thickness δ = 0.005 m. The molecular diffusivity is D_AB = 0.00002 m²/s, and the molar concentration of A is C_A1 = 50 mol/m³ at one face (z = 0) and C_A2 = 20 mol/m³ at the other (z = δ), as shown. The molar flux N_A is most nearly:
1. 0.2 mol/(m²·s)
2. 0.12 mol/(m²·s)
3. 0.28 mol/(m²·s)
4. 0.14 mol/(m²·s)
Show the answer & worked solution
Answer: B.0.12 mol/(m²·s)
N_A = D_AB·(C_A1 − C_A2)/δ = 0.00002·(50 − 20)/0.005 = 0.12 mol/(m²·s). Distractors: the two concentrations ADDED (C_A1 + C_A2 = 70) used as the driving force, 0.28; only the UPSTREAM C_A1 = 50 (forgot to subtract the downstream value), 0.2; and the MEAN concentration (C_A1 + C_A2)/2 = 35 used in place of the difference, 0.14.

What the distractors teach: All three distractors get the driving force wrong and nothing else. Add the two concentrations instead of subtracting them and you get 0.28. Use only the upstream value, forgetting the downstream one exists, and you get 0.2. Use their mean rather than their difference and you get 0.14. Diffusion is driven by a difference in concentration, not by concentration — which sounds obvious written down and is not obvious at minute 190 of a six-hour appointment.

3. Percent overshoot of an under-damped loop

This is the most quietly dangerous problem on any of our practice-problem pages. Process Control is only 4–6 questions, so it is easy to under-prepare — and the formula has one term that barely changes the answer when you drop it.

3
medium
A. Process dynamics & transfer functions
A pressure loop responds as an under-damped second-order system with damping ratio $\zeta = 0.2$ . The percent overshoot of its unit-step response is most nearly:
1. 53.3 %
2. 80 %
3. 20 %
4. 52.7 %
Show the answer & worked solution
Answer: D.52.7 %
$\sqrt{1-\zeta^2} = 0.9798$ , so $OS = e^{-\zeta\pi/\sqrt{1-\zeta^2}}\times100 = e^{-0.641}\times100 = 52.7 %$ . Distractors: the $\sqrt{1-\zeta^2}$ DROPPED, $e^{-\pi\zeta}\times100 = 53.3 %$ (always an overstatement); the damping ratio read as the overshoot, $100\zeta = 20 %$ ; and $100(1-\zeta) = 80 %$ .

What the distractors teach: The correct overshoot is 52.7%. Drop the √(1−ζ²) from the exponent — a small term, and an easy one to lose while transcribing — and you get 53.3%. That is a gap of six-tenths of a percentage point. No sanity check catches it, no order-of-magnitude glance catches it, and both numbers sit in the option list waiting for you. The other two are cruder: read the damping ratio itself as the overshoot for 20%, or compute 100(1−ζ) for 80%. Those you would notice. The 53.3% you would not.

Where the 110 questions come from

Seventeen knowledge areas — more than FE Civil, FE Mechanical or FE Other Disciplines carry. The four marked below are the ones we could find on no other FE specification, checking area names and subtopics across all five of the others.

FE Chemical knowledge areas and question counts, per the NCEES specification effective July 2020
Knowledge area	Questions
MathematicsAnalytic geometry, calculus, differential equations, numerical methods.	6–9
Probability and StatisticsDistributions, expected value, hypothesis testing, regression, data quality.	4–6
Engineering SciencesWork and energy, charge and current, electrical circuits, statics and dynamics fundamentals.	4–6
Materials ScienceChemical and physical properties, corrosion, polymers, material selection.	4–6
Chemistry and BiologyInorganic and organic chemistry, stoichiometry, equilibrium, kinetics, biological processes.	7–11
Fluid Mechanics/DynamicsFluid properties and statics, energy and continuity, pipe flow and fittings, pumps, compressible flow, non-Newtonian fluids.	8–12
ThermodynamicsLaws, properties and phase behaviour, cycles, mixtures, chemical equilibrium.	8–12
Material/Energy BalancesThe largest area on the exam. Steady and unsteady balances, recycle and bypass, reactive systems.	10–15
Heat TransferConduction, convection, radiation, heat exchangers, boiling and condensation.	8–12
Mass Transfer and SeparationChemE onlyDiffusion, distillation, absorption, extraction, membranes, humidification and drying. No other FE exam mentions mass transfer or separation anywhere in its specification.	8–12
Solids HandlingChemE onlyParticle size distributions, size reduction, filtration, fluidisation, storage and transport. Small, and asked nowhere else in the FE programme.	3–5
Chemical Reaction EngineeringChemE onlyRate laws, batch and continuous reactors, conversion and yield, catalysis. Unique to this exam.	7–11
EconomicsTime value of money, cost estimation, project evaluation, depreciation.	4–6
Process DesignChemE onlyProcess flow diagrams, equipment sizing and selection, scale-up, optimisation, utilities. Unique to this exam.	7–11
Process ControlDynamics, feedback and feedforward, controller tuning, stability. Named differently on FE Mechanical and FE Other, which both examine control too.	4–6
Safety, Health, and EnvironmentHazard recognition, exposure limits, process safety, emissions and waste.	5–8
Ethics and Professional PracticeCodes of ethics, professional liability, licensure, agreements.	3–5

One row is worth reading carefully. Material/Energy Balances is the largest area on the paper, and it is NOT in the ChemE-only list — two other FE exams examine mass and energy balances as a subtopic. The genuinely unshared subjects are the four badged above, and Solids Handling among them is tied with Ethics for the smallest area on the exam at 3 to 5 questions. Small does not mean skippable when the whole paper is 110.

For the pass-rate picture across all seven FE disciplines, the companion guide covers it: how hard is the FE exam?

Common questions

What do FE Chemical practice problems actually look like?: Multiple choice, four options, usually phrased 'most nearly', and the options sit close enough that you cannot eliminate them by inspection — on this exam, sometimes within a percentage point of each other. Many carry a figure: a process flow sketch, a stress element, a concentration profile, a sieve curve. NCEES gives 110 questions in a 6-hour appointment, of which 5 hours 20 minutes is exam time, so the working time per question is under three minutes once you allow for reading, a handbook lookup and a check.
What is on the FE Chemical exam that is not on any other FE exam?: Four subjects. Mass Transfer and Separation at 8-12 questions, Chemical Reaction Engineering at 7-11, Process Design at 7-11, and Solids Handling at 3-5. Searching every other FE specification — area names and subtopics alike — none of the five other FE exams mentions mass transfer, separation, reaction engineering, reaction kinetics, process design or solids handling anywhere. Together those four areas carry 25 to 39 of the 110 questions. Note that Material/Energy Balances, despite being the largest area here, is not in that list: two other FE exams cover mass and energy balances as a subtopic.
How many questions are on each FE Chemical topic?: Material/Energy Balances is the largest at 10-15. Fluid Mechanics/Dynamics, Thermodynamics, Heat Transfer, and Mass Transfer and Separation follow at 8-12 each; Chemistry and Biology, Chemical Reaction Engineering, and Process Design at 7-11 each; Mathematics 6-9; Safety, Health and Environment 5-8; Probability and Statistics, Engineering Sciences, Materials Science, Economics and Process Control 4-6 each; Solids Handling and Ethics and Professional Practice 3-5 each. That is 17 knowledge areas, more than FE Civil, Mechanical or Other Disciplines carry, and the ranges sum to between 100 and 153 against an exam of 110.
Is FE Chemical harder than the other FE exams?: Different rather than harder, and the difference is specialisation rather than difficulty. No single area dominates — the largest is under 10% of the paper, the same as on FE Civil and FE Mechanical — but a quarter to a third of the questions come from subjects a candidate can only have met on a chemical engineering degree. Whether that makes it harder depends entirely on what you studied.
What reference material do you get on the FE Chemical exam?: The exam is closed book with an electronic reference: the NCEES FE Reference Handbook is supplied on-screen as a searchable PDF, and no personal copies or outside material are allowed. Practise with the searchable PDF rather than a printed copy — with 17 knowledge areas to move between, finding the right page quickly is a substantial part of the skill being tested.

Build your study plan

Tell us how long you have. We'll budget your hours across every knowledge area using the official NCEES question weights — the heaviest areas get the most time, which is the opposite of how most people study.

Work through seven more

Ten free FE Chemical problems in total — including a sieve analysis from Solids Handling, plane-wall conduction, pipe continuity, capital recovery and normal distributions — each with the full worked solution and every distractor named. No signup.

Try the free FE Chemical set Explore FE Chemical

Format, knowledge areas and appointment length are from the NCEES FE Chemical specification effective beginning with the July 2020 examinations. The per-question time and the comparisons drawn against other FE specifications are ours, not NCEES figures. Specifications and fees change over time — confirm current specifics at ncees.org. Independent study resource; not affiliated with, endorsed by, or sponsored by NCEES.