Chemistry · NDA previous year questions

What is the specific purpose of using potassium hydroxide during the saponification process?

1. A.To obtain soaps which are hard on the skin
2. B.To obtain soaps which are soft on the skin
3. C.To obtain natural fragrance
4. D.To make the saponification very economical

Which one of the following is the correct arrangement of metals in the decreasing order of their reactivity?

1. A.Iron, Sodium, Silver, Copper
2. B.Silver, Copper, Iron, Sodium
3. C.Sodium, Copper, Silver, Iron
4. D.Sodium, Iron, Copper, Silver

Which among the following statements is not correct with respect to allotropes of Carbon?

1. A.Graphite is a good conductor of electricity.
2. B.Diamond is the hardest substance known.
3. C.Fullerene is one of the allotropes of carbon.
4. D.Next to diamond, graphite is the second hardest known substance.

Equal volume of all gases, when measured at the same temperature and pressure, contain an equal number of particles. Who proposed the above law?

1. A.Charles
2. B.Boyle
3. C.Avogadro
4. D.Lussac

Airbags work on the principle of a chemical reaction triggered by the impact producing a gaseous product that causes a sudden volume change. Which one among the following chemical conversions is responsible for this?

1. A.Sodium azide into nitrogen gas
2. B.Solid carbon dioxide into gaseous carbon dioxide
3. C.Carbon dioxide into carbon monoxide
4. D.Sudden conversion of gaseous carbon dioxide into carbon monoxide

What is the total resistance in the following circuit element?

1. A.R/2
2. B.3R
3. C.3R/2
4. D.2R/3

Which one of the following statements about earthquake waves is not correct?

1. A.P waves move faster and are the first to arrive at the surface.
2. B.P waves can travel through gaseous, liquid and solid materials.
3. C.Seismographs located beyond 145° from epicentre can record the arrival of P waves.
4. D.P waves have maximum area covered under its shadow zone.

Which one of the following metals floats in cold water?

1. A.Magnesium
2. B.Calcium
3. C.Potassium
4. D.Copper

Which one of the following solutions is not capable of conducting electricity?

1. A.Copper sulphate
2. B.Sodium chloride
3. C.Sugar
4. D.Sodium hydroxide

Which of the following compounds undergoes/undergo thermal decomposition?

1. A.Zinc oxide
2. B.Silver oxide and zinc oxide
3. C.Silver oxide
4. D.Magnesium oxide

Silver artifacts get tarnished in the air due to the formation of

1. A.silver chloride
2. B.silver oxide
3. C.silver sulphide
4. D.silver sulphate

The breakdown of glucose in cytoplasm results in the formation of

1. A.pyruvate and energy
2. B.pyruvate and carbon dioxide
3. C.pyruvate and oxygen
4. D.pyruvate and nitrogen

Which one of the following salts does not possess water of crystallization?

1. A.Potassium permanganate
2. B.Blue vitriol
3. C.Washing soda
4. D.Mohr’s salt

Bee sting leaves an acid which causes pain and irritation. The acid released is

1. A.tartaric acid
2. B.methanoic acid
3. C.ethanoic acid
4. D.citric acid

Liquid vegetable oils are converted to solid margarine by the use of

1. A.hydrogen gas
2. B.chlorine gas
3. C.carbon dioxide gas
4. D.oxygen gas

Which one of the following metals is most commonly used for making filament of incandescent electric bulbs?

1. A.Aluminium
2. B.Silver
3. C.Copper
4. D.Tungsten

For an element with atomic number 35, which one of the following will be the correct number of electrons in its valence shell based on Bohr's model of an atom?

1. A.1
2. B.3
3. C.5
4. D.7

Which one of the following is not an example of a redox reaction?

1. A.$\mathrm{AlC}{\mathrm{l}}_3+3{\mathrm{H}}_2\mathrm{O}\to \mathrm{Al}(\mathrm{OH}{)}_3+3HCl$
2. B.$2NaH\to 2Na+{\mathrm{H}}_2$
3. C.$4Fe+3{\mathrm{O}}_2\to 2F{\mathrm{e}}_2{\mathrm{O}}_3$
4. D.$\mathrm{CuS}{\mathrm{O}}_4+\mathrm{Zn}\to \mathrm{Cu}+\mathrm{ZnS}{\mathrm{O}}_4$

Which one of the following allotropes of carbon is isomorphous with crystalline silicon?

1. A.Coke
2. B.Diamond
3. C.Graphite
4. D.Coal

Which one of the following is the colour of hydrogen gas?

1. A.Light yellow
2. B.Orange
3. C.Black
4. D.Colourless

Which one of the following is not a pigment?

1. A.Zinc oxide
2. B.Chalk
3. C.White lead
4. D.Silica

Which one of the following statements about fertilizers is not correct?

1. A.Urea is a phosphorus-containing fertilizer.
2. B.Application of fertilizer to the soil increases fertility of the soil.
3. C.Urea can be prepared by action of ammonia and carbon dioxide under high pressure and at high temperature.
4. D.Urea contains more nitrogen than other fertilizers.

Which one of the following is a chemical change?

1. A.Dissolving sugar in water
2. B.Melting of ice
3. C.Crystallization
4. D.Milk turning sour

Which one of the following is the correct molecular formula of ammonium carbonate if the valency of ammonium ion is (+1) and carbonate anion is (-2)?

1. A.$(\mathrm{N}{\mathrm{H}}_4{)}_2\mathrm{C}{\mathrm{O}}_3$
2. B.$\mathrm{N}{\mathrm{H}}_4(\mathrm{C}{\mathrm{O}}_3{)}_2$
3. C.$(\mathrm{N}{\mathrm{H}}_3{)}_2\mathrm{C}{\mathrm{O}}_3$
4. D.$\mathrm{N}{\mathrm{H}}_4\mathrm{C}{\mathrm{O}}_3$

Which one of the following is a covalent compound?

1. A.Calcium oxide
2. B.Sodium nitride
3. C.Silicon carbide
4. D.Zinc sulphide