Chemistry · NDA previous year questions

2018 30 questions

1. Q552018 · 9 Sept 2018

   A stainless steel chamber contains Ar gas at a temperature $T$ and pressure $P$. The total number of Ar atoms in the chamber is $n$. Now Ar gas in the chamber is replaced by $\mathrm{C}{\mathrm{O}}_2$ gas and the total number of $\mathrm{C}{\mathrm{O}}_2$ molecules in the chamber is $n/2$ at the same temperature $T$. The pressure in the chamber now is $P^{\prime }$. Which one of the following relations holds true? (Both the gases behave as ideal gases)

   1. A.$P^{\prime }=P$
   2. B.$P^{\prime }=2P$
   3. C.$P^{\prime }=P/2$
   4. D.$P^{\prime }=P/4$
   Show answer

   Answer: C

2. Q582018 · 9 Sept 2018

   If a free electron moves through a potential difference of 1 kV, then the energy gained by the electron is given by

   1. A.$1.6\times 10^{-19}$ J
   2. B.$1.6\times 10^{-16}$ J
   3. C.$1\times 10^{-19}$ J
   4. D.$1\times 10^{-16}$ J
   Show answer

   Answer: B

3. Q762018 · 9 Sept 2018

   The atomic number of an element is 8. How many electrons will it gain to form a compound with sodium?

   1. A.One
   2. B.Two
   3. C.Three
   4. D.Four
   Show answer

   Answer: B

4. Q772018 · 9 Sept 2018

   A sample of oxygen contains two isotopes of oxygen with masses 16 u and 18 u respectively. The proportion of these isotopes in the sample is $3:1$. What will be the average atomic mass of oxygen in this sample?

   1. A.$17.5$ u
   2. B.$17$ u
   3. C.$16$ u
   4. D.$16.5$ u
   Show answer

   Answer: D

5. Q792018 · 9 Sept 2018

   What is the formula mass of anhydrous sodium carbonate? (Given that the atomic masses of sodium, carbon and oxygen are 23 u, 12 u and 16 u respectively)

   1. A.286 u
   2. B.106 u
   3. C.83 u
   4. D.53 u
   Show answer

   Answer: B

6. Q812018 · 9 Sept 2018

   Which one of the following reactions will give NO (nitric oxide) gas as one of the products?

   1. A.$3Cu+8HN{\mathrm{O}}_3$ (dilute) $\to$
   2. B.$\mathrm{Cu}+4HN{\mathrm{O}}_3$ (conc.) $\to$
   3. C.$4Zn+10HN{\mathrm{O}}_3$ (dilute) $\to$
   4. D.$\mathrm{Zn}+4HN{\mathrm{O}}_3$ (conc.) $\to$
   Show answer

   Answer: A

7. Q822018 · 9 Sept 2018

   Which one of the following is a tribasic acid?

   1. A.Hydrochloric acid
   2. B.Nitric acid
   3. C.Sulphuric acid
   4. D.Phosphoric acid
   Show answer

   Answer: D

8. Q832018 · 9 Sept 2018

   Which one of the following statements is not correct?

   1. A.All carbons in diamond are linked by carbon-carbon single bond.
   2. B.Graphite is layered structure in which layers are held together by weak van der Waals forces.
   3. C.Graphite layers are formed by hexagonal rings of carbon atoms.
   4. D.Graphite layers are held together by carbon-carbon single bond.
   Show answer

   Answer: D

9. Q842018 · 9 Sept 2018

   The solution of which one of the following will have pH less than 7?

   1. A.$\mathrm{NaOH}$
   2. B.$\mathrm{KCl}$
   3. C.$\mathrm{FeC}{\mathrm{l}}_3$
   4. D.$\mathrm{NaCl}$
   Show answer

   Answer: C

10. Q852018 · 9 Sept 2018

    Which one of the following is an oxidation-reduction reaction?

    1. A.$\mathrm{NaOH}+\mathrm{HCl}\to \mathrm{NaCl}+{\mathrm{H}}_2\mathrm{O}$
    2. B.$\mathrm{CaO}+{\mathrm{H}}_2\mathrm{O}\to \mathrm{Ca}(\mathrm{OH}{)}_2$
    3. C.$2Mg+{\mathrm{O}}_2\to 2MgO$
    4. D.$\mathrm{N}{\mathrm{a}}_2\mathrm{S}{\mathrm{O}}_4+\mathrm{BaC}{\mathrm{l}}_2\to \mathrm{BaS}{\mathrm{O}}_4+2NaCl$
    Show answer

    Answer: C

11. Q872018 · 9 Sept 2018

    Which one of the following is the chemical formula of gypsum?

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

    Answer: A

12. Q882018 · 9 Sept 2018

    Which one of the following statements about the law of conservation of mass is correct?

    1. A.A given compound always contains exactly same proportion of elements.
    2. B.When gases combine in a reaction, they do so in a simple ratio by volume, provided all gases are at room temperature.
    3. C.Matter can neither be created nor destroyed.
    4. D.Equal volumes of all gases at same temperature and pressure contain equal number of molecules.
    Show answer

    Answer: C

13. Q952018 · 9 Sept 2018

    MCQ (More than One Correct Answer) The acidic semidigested food coming out of the stomach is neutralized by

    1. A.pancreatic juice
    2. B.duodenal secretion
    3. C.large intestine secretion
    4. D.bile juice
    Show answer

    Answer: A, D

14. Q1002018 · 9 Sept 2018

    Permanent hardness of water cannot be removed by which one of the following methods?

    1. A.Treatment with washing soda
    2. B.Calgon's method
    3. C.Boiling
    4. D.Ion exchange method
    Show answer

    Answer: C

15. Q1012018 · 9 Sept 2018

    Which one of the following is called dry ice?

    1. A.Solid carbon dioxide
    2. B.Liquid carbon dioxide
    3. C.Liquid nitrogen
    4. D.Liquid ammonia
    Show answer

    Answer: A

16. Q1022018 · 9 Sept 2018

    Which one of the following greenhouse gases is in largest concentration in the atmosphere?

    1. A.Chlorofluorocarbon
    2. B.Nitrous oxide
    3. C.Carbon dioxide
    4. D.Methane
    Show answer

    Answer: C

17. Q562018 · 22 Apr 2018

    Which one of the following has maximum inertia?

    1. A.An atom
    2. B.A molecule
    3. C.A one-rupee coin
    4. D.A cricket ball
    Show answer

    Answer: D

18. Q582018 · 22 Apr 2018

    Which one of the following statements about gravitational force is NOT correct?

    1. A.It is experienced by all bodies in the universe
    2. B.It is a dominant force between celestial bodies
    3. C.It is a negligible force for atoms
    4. D.It is same for all pairs of bodies in our universe
    Show answer

    Answer: D

19. Q762018 · 22 Apr 2018

    Which of the following properties is true for a tooth paste?

    1. A.It is acidic
    2. B.It is neutral
    3. C.It is basic
    4. D.It is made up of Calcium phosphate, the material of tooth enamel
    Show answer

    Answer: C

20. Q772018 · 22 Apr 2018

    Which one of the following gives the highest amount of hydrogen ions $({\mathrm{H}}^{+})$?

    1. A.Sodium hydroxide solution
    2. B.Milk of magnesia
    3. C.Lemon juice
    4. D.Gastric juice
    Show answer

    Answer: D

21. Q792018 · 22 Apr 2018

    Which one of the following is the chemical formula of Washing Soda?

    1. A.$\mathrm{NaHC}{\mathrm{O}}_3$
    2. B.$\mathrm{N}{\mathrm{a}}_2\mathrm{C}{\mathrm{O}}_3\cdot 10{\mathrm{H}}_2\mathrm{O}$
    3. C.$\mathrm{N}{\mathrm{a}}_2\mathrm{C}{\mathrm{O}}_3\cdot 5{\mathrm{H}}_2\mathrm{O}$
    4. D.$\mathrm{NaOH}$
    Show answer

    Answer: B

22. Q802018 · 22 Apr 2018

    Which one of the following is NOT true for bleaching powder?

    1. A.It is used as a reducing agent in chemical industries
    2. B.It is used for bleaching wood pulp in paper factories
    3. C.It is used for disinfecting drinking water
    4. D.It is used for bleaching linen in textile industry
    Show answer

    Answer: A

23. Q812018 · 22 Apr 2018

    Which one of the following is the number of water molecules that share with two formula unit $\mathrm{CaS}{\mathrm{O}}_4$ in plaster of Paris?

    1. A.One
    2. B.Two
    3. C.Five
    4. D.Ten
    Show answer

    Answer: A

24. Q822018 · 22 Apr 2018

    How is carbon black obtained?

    1. A.By heating wood at high temperature in absence of air
    2. B.By heating coal at high temperature in absence of air
    3. C.By burning hydrocarbons in a limited supply of air
    4. D.By heating coal at high temperature in presence of air
    Show answer

    Answer: C

25. Q832018 · 22 Apr 2018

    Which one of the following properties is NOT true for graphite?

    1. A.Hybridisation of each carbon atom is $s{p}^3$
    2. B.Hybridisation of each carbon atom is $s{p}^2$
    3. C.Electrons are delocalized over the whole sheet of atoms
    4. D.Each layer is composed of hexagonal rings
    Show answer

    Answer: A