Chemistry · NDA previous year questions

2025 30 questions

1. Q782025 · 14 Sept 2025

   Which one of the following type of medicines is used for treating indigestion ?

   1. A.Analgesic
   2. B.Antiseptic
   3. C.Antibiotic
   4. D.Antacid
   Show answer

   Answer: D

2. Q802025 · 14 Sept 2025

   Which one of the following is NOT a chemical change ?

   1. A.Burning of coal
   2. B.Rusting of metal
   3. C.Melting of ice
   4. D.Reaction of acid with base
   Show answer

   Answer: C

3. Q812025 · 14 Sept 2025

   Which one of the following statements is NOT correct ?

   1. A.The interconversion of states of matter is a physical change
   2. B.During burning of a candle, both chemical and physical changes take place
   3. C.During a physical change, the chemical composition of molecules changes
   4. D.Rusting of iron is a chemical change
   Show answer

   Answer: C

4. Q832025 · 14 Sept 2025
   
   1. A.A - 4, B - 1, C - 2, D - 3
   2. B.A - 4, B - 2, C - 1, D - 3
   3. C.A - 3, B - 2, C - 1, D - 4
   4. D.A - 3, B - 1, C - 2, D - 4 2 2
   Show answer

   Answer: A

5. Q842025 · 14 Sept 2025

   In the following redox reaction, which compound is acting as a reducing agent ? ${\mathrm{N}}_2{\mathrm{H}}_4+2{\mathrm{H}}_2{\mathrm{O}}_2\to {\mathrm{N}}_2+4{\mathrm{H}}_2\mathrm{O}$

   1. A.${\mathrm{H}}_2{\mathrm{O}}_2$
   2. B.${\mathrm{N}}_2{\mathrm{H}}_4$
   3. C.${\mathrm{N}}_2$
   4. D.${\mathrm{H}}_2\mathrm{O}$
   Show answer

   Answer: B

6. Q862025 · 14 Sept 2025

   Which one of the following salts is responsible for temporary hardness of water ?

   1. A.Sulphates of calcium
   2. B.Chlorides of magnesium
   3. C.Bicarbonates of magnesium
   4. D.Sulphates of magnesium
   Show answer

   Answer: C

7. Q872025 · 14 Sept 2025

   Match List I with List II and select the answer using the code given below the Lists : $$\begin{array}{llll}& \text{List I (Reaction)}& & \text{List II (Type)}\\ \text{A.}& \mathrm{CaO}(\mathrm{s})+{\mathrm{H}}_2\mathrm{O}(\mathrm{l})\to \mathrm{Ca}(\mathrm{OH}{)}_2(\mathrm{aq})& \text{1.}& \text{Single Displacement}\\ \text{B.}& \mathrm{CaC}{\mathrm{O}}_3(\mathrm{s})\to \mathrm{CaO}(\mathrm{s})+\mathrm{C}{\mathrm{O}}_2(\mathrm{g})& \text{2.}& \text{Double displacement}\\ \text{C.}& \mathrm{Pb}(\mathrm{s})+\mathrm{CuC}{\mathrm{l}}_2(\mathrm{aq})\to \mathrm{PbC}{\mathrm{l}}_2(\mathrm{aq})+\mathrm{Cu}(\mathrm{s})& \text{3.}& \text{Combination}\\ \text{D.}& \mathrm{N}{\mathrm{a}}_2\mathrm{S}{\mathrm{O}}_4(\mathrm{aq})+\mathrm{BaC}{\mathrm{l}}_2(\mathrm{aq})\to \mathrm{BaS}{\mathrm{O}}_4(\mathrm{s})+2NaCl(\mathrm{aq})& \text{4.}& \text{Decomposition}\end{array}$$

   1. A.A - 2, B - 1, C - 4, D - 3
   2. B.A - 2, B - 4, C - 1, D - 3
   3. C.A - 3, B - 4, C - 1, D - 2
   4. D.A - 3, B - 1, C - 4, D - 2
   Show answer

   Answer: C

8. Q882025 · 14 Sept 2025

   Which one of the following is an endothermic reaction ?

   1. A.$\mathrm{C}{\mathrm{H}}_4(\mathrm{g})+2{\mathrm{O}}_2(\mathrm{g})\to \mathrm{C}{\mathrm{O}}_2(\mathrm{g})+2{\mathrm{O}}_2(\mathrm{g})$
   2. B.${\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6(\mathrm{aq})+6{\mathrm{O}}_2(\mathrm{g})\to 6C{\mathrm{O}}_2(\mathrm{g})+6{\mathrm{H}}_2\mathrm{O}(\mathrm{l})$
   3. C.${\mathrm{N}}_2(\mathrm{g})+3{\mathrm{H}}_2(\mathrm{g})\to 2N{\mathrm{H}}_3(\mathrm{g})$
   4. D.$2Pb(\mathrm{N}{\mathrm{O}}_3{)}_2(\mathrm{s})\to 2PbO(\mathrm{s})+4N{\mathrm{O}}_2(\mathrm{g})+{\mathrm{O}}_2(\mathrm{g})$
   Show answer

   Answer: D

9. Q892025 · 14 Sept 2025

   Which one of the following is known as ‘water gas’ ?

   1. A.${\mathrm{H}}_2\mathrm{O}+\mathrm{C}{\mathrm{O}}_2$
   2. B.$\mathrm{N}{\mathrm{H}}_3$
   3. C.${\mathrm{H}}_2+{\mathrm{N}}_2$
   4. D.$\mathrm{CO}+{\mathrm{H}}_2$
   Show answer

   Answer: D

10. Q962025 · 14 Sept 2025

    Iodized salt is a vital part of our diet as it is essential for the synthesis of

    1. A.Estrogen
    2. B.Thyroxin
    3. C.Insulin
    4. D.Adrenalin
    Show answer

    Answer: B

11. Q522025 · 13 Apr 2025

    Which one of the following statements is correct ?

    1. A.A neutron is formed by combination of an electron and a proton. Therefore, it is neutral
    2. B.The mass of an electron is about 1/2000 times that of a proton
    3. C.An isotope of cobalt is used in the treatment of goiter
    4. D.J. J. Thomson proposed that the nucleus of an atom contains only neutrons
    Show answer

    Answer: B

12. Q532025 · 13 Apr 2025

    Which one of the following particles in the nucleus of an atom was discovered by J. Chadwick?

    1. A.Electron
    2. B.Proton
    3. C.Positron
    4. D.Neutron
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    Answer: D

13. Q542025 · 13 Apr 2025

    Which one of the following findings is NOT observed in Rutherford's Nuclear Model of Atom?

    1. A.There is a neutral centre in an atom called nucleus
    2. B.Nearly all the mass of an atom resides in the nucleus
    3. C.The electrons revolve around the nucleus in a circular path
    4. D.The size of a nucleus is very small as compared to the size of atom
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    Answer: A

14. Q552025 · 13 Apr 2025

    Element X forms a chloride with the formula XCl₂, which is a solid with high melting point. X would most likely be in the same group of periodic table as

    1. A.Na
    2. B.Al
    3. C.Mg
    4. D.K
    Show answer

    Answer: C

15. Q562025 · 13 Apr 2025

    Which one of the following oxides is a neutral oxide?

    1. A.CO
    2. B.CO₂
    3. C.Na₂O
    4. D.MgO
    Show answer

    Answer: A

16. Q592025 · 13 Apr 2025

    Which one of the following statements is NOT correct?

    1. A.Half mole of nitrogen gas is measured 11·2 litre at STP
    2. B.17 gram of ammonia gas contains 6·022 × 10²³ molecules at STP
    3. C.22·4 litre of CO₂ gas at STP contains 44 gram of molecules
    4. D.4 gram of hydrogen gas contains 6·022 × 10²³ molecules
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    Answer: D

17. Q602025 · 13 Apr 2025

    Which one of the following statements about a compound is NOT correct?

    1. A.A compound is a substance composed of two or more elements, chemically combined in a fixed proportion
    2. B.Properties of a compound are different from its constituent elements
    3. C.A compound is an impure substance
    4. D.The constituents of a compound can be separated only by chemical or electrochemical reactions
    Show answer

    Answer: C

18. Q612025 · 13 Apr 2025

    Match List I with List II and select the answer using the code given below the Lists: $$\begin{array}{ll}\text{List I (Chemical Name)}& \text{List II (Chemical Formula)}\\ \text{A. Washing soda}& \text{1. }\mathrm{CaOC}{\mathrm{l}}_2\\ \text{B. Baking soda}& \text{2. }\mathrm{NaHC}{\mathrm{O}}_3\\ \text{C. Bleaching powder}& \text{3. }\mathrm{N}{\mathrm{a}}_2\mathrm{C}{\mathrm{O}}_3\cdot 10{\mathrm{H}}_2\mathrm{O}\\ \text{D. Gypsum}& \text{4. }\mathrm{CaS}{\mathrm{O}}_4\cdot 2{\mathrm{H}}_2\mathrm{O}\end{array}$$ Code:

    1. A.(a) - (4) , (b) - (2) , (c) - (1) , (d) - (3)
    2. B.(a) - (4) , (b) - (1) , (c) - (2) , (d) - (3)
    3. C.(a) - (3) , (b) - (1) , (c) - (2) , (d) - (4)
    4. D.(a) - (3) , (b) - (2) , (c) - (1) , (d) - (4)
    Show answer

    Answer: D

19. Q622025 · 13 Apr 2025

    Which one of the following nitrogen oxides may dimerize?

    1. A.N₂O
    2. B.NO₂
    3. C.N₂O₃
    4. D.N₂O₅
    Show answer

    Answer: B

20. Q632025 · 13 Apr 2025

    Which one of the following statements regarding oxidation and reduction reactions is NOT correct?

    1. A.If a substance loses hydrogen during reaction, it is reduced
    2. B.If a substance loses oxygen during reaction, it is reduced
    3. C.If a substance gains hydrogen during reaction, it is reduced
    4. D.If a substance gains oxygen during reaction, it is oxidized
    Show answer

    Answer: A

21. Q652025 · 13 Apr 2025

    For acid rain, the pH of rain water should be less than

    1. A.7·0
    2. B.6·6
    3. C.5·6
    4. D.8·0
    Show answer

    Answer: C

22. Q692025 · 13 Apr 2025

    A chain of peptide containing linear sequences of amino acid linked by peptide bonds best represent the

    1. A.Primary structure
    2. B.Secondary structure
    3. C.Tertiary structure
    4. D.Quaternary structure
    Show answer

    Answer: A

23. Q712025 · 13 Apr 2025

    What happens when the fat and oil containing food materials are left outside for a long time?

    1. A.Fats and oils in the food get oxidized
    2. B.Fats and oils in the food get reduced
    3. C.Fats and oils in the food get ice-covered
    4. D.No reaction takes place
    Show answer

    Answer: A

24. Q872025 · 13 Apr 2025

    Which one of the following is NOT a basic property of electric charge?

    1. A.Charges can be added
    2. B.Charge is conserved
    3. C.Charge on a body is always an integral multiple of an electron or a proton charge
    4. D.Charges can be created and destroyed in an isolated system
    Show answer

    Answer: D

25. Q932025 · 13 Apr 2025

    If the speed of light in carbon disulfide and vacuum is $X$ and $Y$ respectively, then

    1. A.$X<Y$
    2. B.$X>Y$
    3. C.$X\ge Y$
    4. D.$X=Y$
    Show answer

    Answer: A