UTpaper

Free mock tests & test series

RRB JE · General Science

Chemistry: Reactions Previous Year Questions

28 Chemistry: Reactions (General Science) questions asked in RRB JE previous year papers, each with the correct answer and explanation. Read them free on UTpaper, or attempt the full papers as timed online tests.

  • 28 questions
  • Official answer key
  • Free
Attempt RRB JE papers →All General Science questions

Other General Science topics

Physics: Electricity & Magnetism 59Physics: Light & Sound 32Chemistry: Acids, Bases & Salts 28Physics: Motion & Force 21Biology: Cell & Genetics 19Physics: Heat 18Biology: Plants 17Chemistry: Atoms & Periodic Table 12Biology: Nutrition & Diseases 11Chemistry: Carbon & Compounds 8
Q1RRB JE CBT-1, 18 Dec 2024, Shift 3 (4:30 PM)
Which of the following is an example of exothermic combination reaction?
  1. ARespiration
  2. BAmmonium chloride dissolved in water
  3. CPhotosynthesis
  4. DQuick lime dissolved in water
Show answerHide answer

Correct answer: (D) Quick lime dissolved in water

Q2RRB JE CBT-1, 18 Dec 2024, Shift 3 (4:30 PM)
What happens when sodium hydroxide reacts with copper (II) sulfate solution?
  1. ANo reaction occurs.
  2. BSodium sulfate is formed.
  3. CCopper metal is deposited.
  4. DCopper(II) hydroxide precipitates.
Show answerHide answer

Correct answer: (D) Copper(II) hydroxide precipitates.

Q3RRB JE CBT-1, 18 Dec 2024, Shift 3 (4:30 PM)
Neutralisation reaction is a type of:
  1. Acombination reaction
  2. Bdecomposition reaction
  3. Cdisplacement reaction
  4. Ddouble displacement reaction
Show answerHide answer

Correct answer: (D) double displacement reaction

Q4RRB JE CBT-1, 18 Dec 2024, Shift 2 (12:45 PM)
What is the general form of a combination reaction?
  1. AA → B + C
  2. BA + B → AB
  3. CAB + CD → AC + BD
  4. DAB → A + B
Show answerHide answer

Correct answer: (B) A + B → AB

Q5RRB JE CBT-1, 18 Dec 2024, Shift 1 (9:00 AM)
In the reaction CuO+H₂→Cu+H₂O, the substance reduced is:
  1. ACuO
  2. BH₂O
  3. CH₂
  4. DCu
Show answerHide answer

Correct answer: (A) CuO

Q6RRB JE CBT-1, 18 Dec 2024, Shift 1 (9:00 AM)
When lead nitrate is heated, it decomposes to form lead monoxide (PbO), nitrogen dioxide (NO₂), and oxygen (O₂). The brown gas seen during the reaction is:
  1. Anitrogen dioxide (NO₂)
  2. Blead monoxide (PbO)
  3. Coxygen (O₂)
  4. Dnitric oxide (NO)
Show answerHide answer

Correct answer: (A) nitrogen dioxide (NO₂)

Q7RRB JE CBT-1, 18 Dec 2024, Shift 1 (9:00 AM)
Which of the following reactions is an example of a precipitation reaction?
  1. ACaCO₃ → CaO + CO₂
  2. BHCl + NaOH → NaCl + H₂O
  3. C2H₂ + O₂ → 2H₂O
  4. DNaCl + AgNO₃ → NaNO₃ + AgCl
Show answerHide answer

Correct answer: (D) NaCl + AgNO₃ → NaNO₃ + AgCl

Q8RRB JE CBT-1, 18 Dec 2024, Shift 1 (9:00 AM)
Which of the following represents a combination reaction?
  1. ACaO + H₂O → Ca(OH)₂
  2. BCaCO₃ → CaO + CO₂
  3. C2KClO₃ → 2KCl + 3O₂
  4. DNaCl + AgNO₃ → AgCl + NaNO₃
Show answerHide answer

Correct answer: (A) CaO + H₂O → Ca(OH)₂

Q9RRB JE CBT-1, 18 Dec 2024, Shift 1 (9:00 AM)
When two elements react to form a compound, it can be classified as:
  1. Adisplacement
  2. Bdouble displacement
  3. Cdecomposition
  4. Dcombination
Show answerHide answer

Correct answer: (D) combination

Q10RRB JE CBT-1, 17 Dec 2024, Shift 3 (4:30 PM)
Oxidation of metals in the presence of acids or moisture is called:
  1. Acorrosion
  2. Bneutralisation
  3. Crancidity
  4. Drusting
Show answerHide answer

Correct answer: (A) corrosion

Q11RRB JE CBT-1, 17 Dec 2024, Shift 3 (4:30 PM)
What is the role of chlorine gas in the preparation of bleaching powder?
  1. AIt reacts with dry slaked lime to form bleaching powder.
  2. BIt reacts with water to produce hydrogen peroxide.
  3. CIt is used as a catalyst for the reaction.
  4. DIt is used to neutralise calcium hydroxide.
Show answerHide answer

Correct answer: (A) It reacts with dry slaked lime to form bleaching powder.

Q12RRB JE CBT-1, 17 Dec 2024, Shift 2 (12:45 PM)
Which of the following statements best describes what happens in a double displacement reaction?
  1. AElectrons are transferred between atoms.
  2. BIons in two compounds switch places to form two new compounds.
  3. CTwo elements combine to form a compound.
  4. DA compound breaks down into simpler substances.
Show answerHide answer

Correct answer: (B) Ions in two compounds switch places to form two new compounds.

Q13RRB JE CBT-1, 17 Dec 2024, Shift 2 (12:45 PM)
A double displacement reaction typically involves the exchange of:
  1. Aneutrons
  2. Bprotons
  3. Celectrons
  4. Dions
Show answerHide answer

Correct answer: (D) ions

Q14RRB JE CBT-1, 17 Dec 2024, Shift 1 (9:00 AM)
What is formed when sodium sulfate reacts with barium chloride in a double displacement reaction?
  1. ASodium sulfate and barium chloride
  2. BSodium chloride and barium hydroxide
  3. CSodium chloride and barium sulfate
  4. DSodium hydroxide and barium chloride
Show answerHide answer

Correct answer: (C) Sodium chloride and barium sulfate

Q15RRB JE CBT-1, 17 Dec 2024, Shift 1 (9:00 AM)
In the reaction: Zn + CuSO₄ → ZnSO₄ + Cu, what happens to zinc?
  1. AZinc is reduced.
  2. BZinc loses electrons.
  3. CZinc is oxidised.
  4. DZinc does not change.
Show answerHide answer

Correct answer: (C) Zinc is oxidised.

Explanation

Official answer key: (3) Zinc is oxidised. Option 2 (Zinc loses electrons) is also correct, because losing electrons is what oxidation means. Zn → Zn²⁺ + 2e⁻, so zinc is oxidised. Scoring follows the official key.

Q16RRB JE CBT-1, 16 Dec 2024, Shift 3 (4:30 PM)
In the reaction MnO₂ + 4HCl → MnCl₂ + 2H₂O + Cl₂, what is being reduced?
  1. AHydrogen (H)
  2. BChlorine (Cl)
  3. COxygen (O)
  4. DManganese (Mn)
Show answerHide answer

Correct answer: (D) Manganese (Mn)

Q17RRB JE CBT-1, 16 Dec 2024, Shift 3 (4:30 PM)
Which of the following best describes a combination reaction?
  1. AA compound breaks down into simpler substances
  2. BA reaction where a product releases gas
  3. CTwo elements combine to form a compound
  4. DIons exchange between two compounds
Show answerHide answer

Correct answer: (C) Two elements combine to form a compound

Q18RRB JE CBT-1, 16 Dec 2024, Shift 3 (4:30 PM)
Double displacement reactions usually occur in:
  1. Aaqueous solution
  2. Bgaseous state
  3. Call three states
  4. Dsolid state
Show answerHide answer

Correct answer: (A) aqueous solution

Q19RRB JE CBT-1, 16 Dec 2024, Shift 2 (12:45 PM)
Combination reaction can be represented as:
  1. AABC → AB + C
  2. BAB + CD → AD + CD
  3. CAB + C → CB + A
  4. DAB + C → ABC
Show answerHide answer

Correct answer: (D) AB + C → ABC

Q20RRB JE CBT-1, 16 Dec 2024, Shift 1 (9:00 AM)
On oxidation, silver changes its colour to _______ and copper changes its colour to _______.
  1. Agrey; green
  2. Bblack; green
  3. Cblack; blue
  4. Dgrey; blue
Show answerHide answer

Correct answer: (B) black; green

Q21RRB JE CBT-1, 16 Dec 2024, Shift 1 (9:00 AM)
Which of the following reactions does NOT represent a neutralisation reaction?
  1. AH₂SO₄ + Ca(OH)₂ → CaSO₄ + 2H₂O
  2. BCH₃COOH + NaOH → CH₃COONa + H₂O
  3. CHCl + NaOH → NaCl + H₂O
  4. DNa₂CO₃ + HCl → NaCl + CO₂ + H₂O
Show answerHide answer

Correct answer: (D) Na₂CO₃ + HCl → NaCl + CO₂ + H₂O

Q22RRB JE CBT-1, 20 Feb 2026, Shift 3 (4:30 PM)
A town replaces all plastic bags with cloth bags. Which chain reaction is expected in the ecosystem?
  1. ACloth bags cause soil toxicity
  2. BPlastic still enters the food chain
  3. CMore plastic accumulates in water bodies
  4. DReduced pollution and decreased biological magnification
Show answerHide answer

Correct answer: (D) Reduced pollution and decreased biological magnification

Q23RRB JE CBT-1, 20 Feb 2026, Shift 2 (12:45 PM)
In a redox reaction, what is the role of a 'reducing agent'?
  1. AIt is a catalyst that speeds up the reaction.
  2. BIt is an agent that helps other substances to be oxidized.
  3. CIt is a substance that causes reduction and itself gets oxidized.
  4. DIt is a substance that only participates in decomposition reactions.
Show answerHide answer

Correct answer: (C) It is a substance that causes reduction and itself gets oxidized.

Q24RRB JE CBT-1, 20 Feb 2026, Shift 2 (12:45 PM)
Why is nitrogen gas used to prevent oxidation in bags containing foods such as chips?
  1. ANitrogen gas makes chips crispier.
  2. BNitrogen gas inhibits oxidation by replacing oxygen.
  3. CNitrogen gas accelerates oxidation.
  4. DNitrogen gas enhances the taste of the food.
Show answerHide answer

Correct answer: (B) Nitrogen gas inhibits oxidation by replacing oxygen.

Q25RRB JE CBT-1, 19 Feb 2026, Shift 3 (4:30 PM)
Which process is used to convert zinc carbonate ore into zinc oxide before reduction?
  1. AHeating strongly in limited air
  2. BHeating with aluminium powder
  3. CHeating with carbon powder
  4. DHeating strongly in excess air
Show answerHide answer

Correct answer: (A) Heating strongly in limited air

Q26RRB JE CBT-1, 19 Feb 2026, Shift 3 (4:30 PM)
Select the correct option regarding the following two statements labelled Assertion (A) and Reason (R). Assertion (A): Excess accumulation of biodegradable waste can also create environmental problems. Reason (R): Slow decomposition may lead to foul smell and spread of disease.
  1. ABoth A and R are true, and R is the correct explanation of A
  2. BA is true, but R is false
  3. CBoth A and R are true, but R is not the correct explanation of A
  4. DA is false, but R is true
Show answerHide answer

Correct answer: (A) Both A and R are true, and R is the correct explanation of A

Q27RRB JE CBT-1, 19 Feb 2026, Shift 3 (4:30 PM)
Why is mercury obtained from cinnabar ore through two heating steps instead of direct reduction?
  1. AMercury sulphide must first change into oxide
  2. BMercury metal reacts with oxygen on heating
  3. CMercury oxide forms only in absence of air
  4. DMercury sulphide melts before decomposition
Show answerHide answer

Correct answer: (A) Mercury sulphide must first change into oxide

Q28RRB JE CBT-1, 19 Feb 2026, Shift 1 (9:00 AM)
When two aqueous solutions react inside a sealed flask and form products, what happens to the total mass of the system?
  1. AIt fluctuates during reaction
  2. BIt increases due to gas formation
  3. CIt decreases due to precipitation
  4. DIt remains unchanged throughout
Show answerHide answer

Correct answer: (D) It remains unchanged throughout

How to use these RRB JE General Science questions

Every question here was asked in a real RRB JE paper; the paper and shift are shown on the card, and the number opens the question on its own page. Try each one before tapping Show answer, then attempt the full RRB JE papers as timed tests to check your speed under exam conditions.

More RRB JE subjects

Mathematics 561General Awareness 379Reasoning 316Environment & Pollution Control 18