PracticeVideosBlogFlashcardsEspañol
All Practice Exams

Free Practice Questions for Engineer Chemical Industry

Exam-style questions and explanations by OpenExamPrep.

✓ No registration✓ No credit card
100+ Questions
100% Free

Loading practice questions...

Same family resources

Explore More South Korea National Technical Qualifications in Engineering (HRD Korea)

Continue into nearby exams from the same family. Each card keeps practice questions, study guides, flashcards, videos, and articles in one place.

Engineer Chemical Analysis (화학분석기사, South Korea)

Practice Questions

Engineer Civil Engineering (토목기사, South Korea)

Practice Questions

Engineer Concrete (콘크리트기사, South Korea)

Practice Questions

Engineer Electric Railway (전기철도기사, South Korea)

Practice Questions

Engineer Electric Work (전기공사기사, South Korea)

Practice Questions

Engineer Electricity (전기기사, South Korea)

Practice Questions
Exam Review

Key Facts: Engineer Chemical Industry Exam

80 items

Official written paper length (4 subjects × 20 items)

Q-Net Engineer-grade grading method; Enforcement Rule [별표 8]; Q-Net 화공기사 page

120 minutes

Written examination duration (30 minutes per subject)

Q-Net 필기시험 접수안내 (기사·산업기사 과목별 30분)

40 / 60

Written per-subject floor (과락) and overall passing average

Q-Net 검정기준 및 방법 (기사)

KRW 19,400

Written registration fee on Q-Net 화공기사 page

Q-Net crf005 jmCd=1110, checked 2026-09-20

KRW 55,700

Practical registration fee on Q-Net 화공기사 page

Q-Net crf005 jmCd=1110, checked 2026-09-20

2 years

Written-pass exemption period from pass date

National Technical Qualifications Act Enforcement Decree Article 21

화공기사 is HRD Korea's Engineer-grade qualification under 고용노동부 (Ministry of Employment and Labor) for chemical engineering professionals. The written CBT paper consists of 80 four-option questions across four subjects (20 questions each, 120 minutes total), requiring at least 40 points per subject (과락 floor) and an overall average of 60 points. A subsequent composite practical examination (KRW 55,700) tests chemical engineering design calculations and bench distillation techniques. OpenExamPrep provides 100 independent English practice MCQs covering those written topics.

Sample Engineer Chemical Industry Practice Questions

Try these sample questions to review concepts for the Engineer Chemical Industry exam. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1In the Haber–Bosch ammonia synthesis used throughout 공업합성 (industrial synthesis) study for 화공기사, nitrogen and hydrogen are converted over a promoted iron catalyst. Which stoichiometry and qualitative operating policy are correct?
A.N2 + 3 H2 ⇌ 2 NH3; high pressure favors ammonia, while the temperature is a compromise between equilibrium and rate
B.N2 + H2 ⇌ NH3; low pressure and the highest possible temperature both maximize equilibrium conversion
C.2 N2 + H2 ⇌ 2 NH3; atmospheric pressure and a platinum gauze are required
D.N2 + 3 H2 ⇌ 2 NH3; vacuum operation is required because the reaction increases the number of gas moles
Explanation: Ammonia synthesis follows N2 + 3 H2 ⇌ 2 NH3 over a promoted iron catalyst. The reaction is exothermic and reduces the number of gas moles, so high pressure favors the product, while the industrial temperature (typically about 400–500 °C) is high enough for a useful rate without destroying the equilibrium conversion.
2In the contact process (접촉법) for sulfuric acid, which catalyst and SO2-oxidation practice are used industrially?
A.Nickel reforming catalyst at 800 °C; SO2 is liquefied and oxidized by air without a catalyst
B.Vanadium(V) oxide (V2O5) at roughly 420–450 °C and near-atmospheric pressure; SO3 is absorbed in concentrated sulfuric acid to make oleum
C.Finely divided iron at 200 bar; SO3 is absorbed directly in pure water to avoid mist
D.Platinum–rhodium gauze at 850 °C; the product is oleum distilled from nitric acid
Explanation: Modern contact plants oxidize SO2 to SO3 over a V2O5 catalyst near 450 °C and near-atmospheric pressure. Direct absorption of SO3 in water produces an unmanageable acid mist, so SO3 is absorbed in concentrated H2SO4 to form oleum, which is then diluted to the desired sulfuric acid strength.
3A membrane chlor-alkali (클로르알칼리) electrolyzer decomposes purified sodium chloride brine. Which set of products leaves the cell?
A.HCl and NaOCl as the only cell products, with no hydrogen
B.Na2CO3, CaCl2, and recycled ammonia
C.Cl2 at the anode, H2 and NaOH at the cathode/caustic compartment
D.Na metal at the cathode, Cl2 at the anode, and O2 in the brine
Explanation: In a membrane chlor-alkali cell, chloride is oxidized to chlorine at the anode. Water is reduced to hydrogen at the cathode, and sodium ions crossing the cation-exchange membrane combine with hydroxide to yield NaOH. The overall reaction is 2 NaCl + 2 H2O → 2 NaOH + Cl2 + H2.
4The Ostwald process (암모니아 산화법) manufactures nitric acid from ammonia. Which statement is correct?
A.Ammonia is oxidized over V2O5 at 450 °C and absorbed in oleum
B.Nitric acid is made by direct combination of N2 and O2 over promoted iron at 200 bar
C.Ammonia is absorbed in water first; the solution is then electrolyzed to HNO3 and H2
D.Ammonia is oxidized with air over a Pt–Rh gauze to NO, which is further oxidized to NO2 and absorbed in water to form HNO3
Explanation: Ostwald oxidation converts NH3 to NO on a platinum–rhodium gauze at high temperature. NO is oxidized to NO2 (and N2O4) and then absorbed in water, producing nitric acid and regenerating some NO that is recycled. Excess air is supplied to drive the oxidation steps.
5In the Solvay (암모니아-소다) process, what is the principal commercial product, and which statement about ammonia is correct?
A.Soda ash (Na2CO3); ammonia is recycled rather than consumed as a net stoichiometric feedstock
B.Caustic soda (NaOH); ammonia is oxidized to nitric acid in the same kiln
C.Sodium metal; ammonia is the reducing agent that displaces Na from NaCl
D.Chlorine gas; ammonia is added only to dry the Cl2 product
Explanation: The Solvay ammonia–soda process converts brine and limestone into soda ash (Na2CO3), with CaCl2 as the main by-product. Ammonia is used to generate ammonium bicarbonate intermediates and is recovered and recycled, so it is not a net raw material in a well-operated plant.
6In a steam cracker (수증기 분해) processing ethane or naphtha, which product is the primary light-olefin target and which thermal character is correct?
A.Sulfuric acid; steam is added only to absorb SO3 as oleum
B.Ethylene; the cracking reactions are strongly endothermic and require high temperature and short residence time
C.Methanol; the reactions are strongly exothermic and are run adiabatically in a packed-bed methanol converter
D.Ammonia; the coil is filled with promoted iron catalyst at 200 bar
Explanation: Steam cracking is the principal industrial route to ethylene (and propylene from liquid feeds). Carbon–carbon bond scission is endothermic, so radiant coils operate at high temperature (on the order of 800 °C) with steam dilution and short residence time, followed by rapid quench to limit secondary reactions.
7Which statement correctly classifies the chain-growth polymer polyethylene (PE) used in 공업합성 polymer topics?
A.PE is a condensation polyamide analogous to nylon-6,6
B.PE is a thermoset phenolic resin formed from phenol and formaldehyde
C.PE is an addition (chain-growth) polymer of ethylene; no small-molecule condensate is produced in the propagation step
D.PE is a condensation polymer of ethylene glycol and terephthalic acid
Explanation: Polyethylene is produced by addition polymerization of ethylene. Each monomer C=C unit is incorporated into the chain without releasing a condensate such as water. Condensation polymers (PET, nylon, phenolics) form by step-growth reactions that typically expel a small molecule.
8What is the monomer used to manufacture polyvinyl chloride (PVC)?
A.Propylene (CH2=CHCH3)
B.Styrene (C6H5CH=CH2)
C.Tetrafluoroethylene (CF2=CF2)
D.Vinyl chloride (chloroethene, CH2=CHCl)
Explanation: PVC is the addition polymer of vinyl chloride (chloroethene). Industrial vinyl chloride is typically obtained from ethylene via EDC (1,2-dichloroethane) cracking. The other olefins are the monomers for PP, PS, and PTFE, respectively.
9In petrochemical aromatics recovery, BTX refers to which group of compounds?
A.Benzene, toluene, and xylenes
B.Butane, toluene, and xenon
C.Benzene, turpentine, and xylan
D.Butadiene, toluene, and p-xylene only, excluding benzene
Explanation: BTX is the standard petrochemical abbreviation for the aromatic slate benzene, toluene, and xylenes. These aromatics are recovered from catalytic reformate and pyrolysis gasoline and are feedstocks for styrene, phenol, PTA, and other intermediates.
10Compared with the historical mercury amalgam chlor-alkali cell, why has the ion-exchange membrane cell become the preferred technology?
A.It converts NaCl directly into soda ash without forming chlorine
B.It avoids mercury inventory and emissions while still producing Cl2, H2, and concentrated NaOH
C.It produces sodium metal instead of NaOH, which is easier to ship
D.It requires no electrical power because the membrane generates a galvanic voltage
Explanation: Membrane cells still accomplish the chlor-alkali stoichiometry but replace the mercury cathode with a cation-exchange membrane that keeps chlorine and caustic separate. Eliminating mercury removes a major environmental and occupational hazard and yields high-purity NaOH without a mercury-removal step.

About the Engineer Chemical Industry Exam

Engineer Chemical Industry (화공기사) is South Korea's premier Engineer-grade national technical qualification for chemical process engineers, plant operators, and industrial chemists. Administered by HRD Korea on Q-Net under the Ministry of Employment and Labor (고용노동부), the certification validates expertise in industrial chemical synthesis, fluid and thermal transport phenomena, unit operations, chemical reactor design and kinetics, and automated process control. Following the 80-question written examination, successful candidates take a composite practical exam combining chemical engineering calculations (필답형) and a laboratory simple/fractional distillation experiment (작업형). The questions on this page provide an independent English-language MCQ study adaptation designed to master core concepts, calculation mechanics, and regulatory competencies.

Exam sponsor: HRD Korea (Q-Net) / Ministry of Employment and Labor (고용노동부). The requirements and fees below concern the certification or admission exam, separate from our free practice resources.

Assessment

Written CBT examination covering Industrial Synthesis (공업합성), Unit Process Management (단위공정관리), Reaction Operation (반응운전), and Chemical Process Instrumentation & Control (화공계측제어) (20 items and 30 minutes each, total 80 items and 120 minutes), followed by a composite practical examination in Chemical Engineering Practice (화학공정 실무: 55-point written design exam + 45-point laboratory distillation bench test). OpenExamPrep study weights match the four equal written subjects.

Time Limit

120 minutes for the four written subjects (30 minutes each); approximately 5.5 hours for the composite practical examination

Passing Score

Written: 40+ per subject (과락 floor) and 60 average out of 100; practical: 60/100

Exam / Certification Fees

KRW 19,400 written / KRW 55,700 practical (Q-Net, 2026-09-20)

Exam sponsor website

Fees, eligibility, and exam policies can change. Confirm them with the exam sponsor before applying or paying.

Official sources

Our practice resources: topics covered

We aim to reflect publicly available exam outlines and topic information in our study resources. Coverage, format, and difficulty may differ from the actual exam, and we cannot guarantee that every detail is accurate or current. Confirm exam requirements, fees, and policies with the official exam sponsor.

25%

Industrial Synthesis (공업합성)

Petrochemical industry processes (cracking, reforming, FCC, C2/C3/C4 olefins, BTX aromatics), polymer synthesis (addition, condensation, radical/ionic/Ziegler-Natta mechanisms, engineering plastics), inorganic manufacturing (H2SO4, NH3, HNO3, chlor-alkali, soda ash), industrial catalysis, and green chemistry metrics.

25%

Unit Process Management (단위공정관리)

Fluid mechanics in piping systems (Bernoulli, Hagen-Poiseuille, friction factor, pump curves, NPSH), heat transfer (conduction, convection, overall U, LMTD, shell-and-tube design), and mass transfer separations (distillation McCabe-Thiele, gas absorption HTU/NTU, extraction, drying, filtration).

25%

Reaction Operation (반응운전)

Chemical engineering thermodynamics (laws of thermodynamics, enthalpy, Gibbs free energy, equilibrium constants, van 't Hoff equation, fugacity/activity), reaction kinetics (rate laws, half-life, Arrhenius), and reactor design (batch, CSTR, PFR design equations, space time, sizing comparisons, thermal runaway).

25%

Chemical Process Instrumentation & Control (화공계측제어)

Process sensors (temperature, pressure, flow, level), control valve sizing (Cv) and fail-safe characteristics, dynamic response modeling (first- and second-order systems), feedback PID control, closed-loop stability (Routh-Hurwitz, Bode, Nyquist), tuning methods, and process safety (PSM, HAZOP, SIS/SIL).

Preparing for the Engineer Chemical Industry Exam

What You Need to Know

  • Passing score: Written: 40+ per subject (과락 floor) and 60 average out of 100; practical: 60/100
  • Assessment: Written CBT examination covering Industrial Synthesis (공업합성), Unit Process Management (단위공정관리), Reaction Operation (반응운전), and Chemical Process Instrumentation & Control (화공계측제어) (20 items and 30 minutes each, total 80 items and 120 minutes), followed by a composite practical examination in Chemical Engineering Practice (화학공정 실무: 55-point written design exam + 45-point laboratory distillation bench test). OpenExamPrep study weights match the four equal written subjects.
  • Time limit: 120 minutes for the four written subjects (30 minutes each); approximately 5.5 hours for the composite practical examination
  • Exam / certification fees: KRW 19,400 written / KRW 55,700 practical (Q-Net, 2026-09-20) Official sources

Using Our Practice Resources

  • Work through all 100 available questions
  • Review every answer and explanation
  • Track weak areas and revisit them
  • Use our AI tutor for tough concepts

Engineer Chemical Industry: Suggested Study Strategy

1Master the fundamental calculation problems in Unit Process Management and Reaction Operation, especially McCabe-Thiele distillation stages, CSTR/PFR sizing equations, and LMTD heat transfer, which appear consistently in both written and practical examinations.
2Avoid the 40-point per-subject failure floor (과락) by maintaining balanced study across all four subjects; many test-takers struggle specifically with transfer functions and Bode stability in Process Control or detailed reaction mechanisms in Industrial Synthesis.
3Practice unit conversions meticulously (e.g., bar to Pa, kcal to kJ, poise to Pa·s, rpm to rad/s); calculation errors due to inconsistent dimensional units are the leading cause of missed points.
4Prepare thoroughly for the laboratory bench practical by practicing pycnometer density measurements, refractometer calibration, and Rayleigh equation numerical integrations before test day.

Frequently Asked Questions

What is Engineer Chemical Industry (화공기사)?

Engineer Chemical Industry (화공기사) is South Korea's premier national technical qualification for chemical engineers, administered by the Human Resources Development Service of Korea (HRD Korea / Q-Net) under the Ministry of Employment and Labor (고용노동부). It certifies technical competence in chemical plant unit operations, reactor operation, process control, and industrial chemical synthesis.

What is the official exam structure and passing standard in 2026?

The written examination consists of 80 four-option multiple-choice questions across four subjects: Industrial Synthesis, Unit Process Management, Reaction Operation, and Chemical Process Instrumentation & Control (20 questions each, 120 minutes total). To pass, candidates must score at least 40 points in every subject ( 과락 floor) and achieve an overall average of 60 points or higher out of 100. Successful candidates qualify for the practical examination.

How does the practical examination (실기시험) work for 화공기사?

The practical exam is a composite examination (복합형) consisting of two mandatory parts: a written response test (필답형, 1.5 hours, 55 points) covering chemical engineering design, mass/energy balances, and equipment sizing; and an in-person laboratory experiment (작업형, ~4 hours, 45 points) involving binary mixture distillation (typically ethanol-water), refractive index / density pycnometer analysis, and Rayleigh distillation yield calculations. The practical passing score is 60 points out of 100.

What are the official registration fees and validity periods?

According to the Q-Net 화공기사 qualification schedule checked on 2026-09-20, the written examination fee is KRW 19,400 and the practical examination fee is KRW 55,700. Under Article 21 of the National Technical Qualifications Act Enforcement Decree, candidates who pass the written exam are exempt from retaking the written exam for 2 years from the pass announcement date.

What language is the official examination conducted in, and how should this bank be used?

The official Q-Net examination is administered in Korean. OpenExamPrep provides an independent, comprehensive English-language study adaptation with authentic technical calculations and standard Korean technical terms in parentheses. It is designed to reinforce core chemical engineering fundamentals, equipment design formulas, and test-taking speed for both Korean and international engineers.