Chemistry · NDA previous year questions

The setting time of cement is lowered by adding

1. A.oxides of aluminium
2. B.gypsum
3. C.oxides of magnesium
4. D.silica

Which one of the following gases gives acidic solution on dissolving in water ?

1. A.Hydrogen
2. B.Carbondioxide
3. C.Nitrogen
4. D.Oxygen

How many moles of hydrogen atom are present in one mole of Aluminium hydroxide ?

1. A.One mole
2. B.Two moles
3. C.Three moles
4. D.Four moles

Which one of the following species is not capable of showing disproportionation reaction?

1. A.$\mathrm{Cl}{\mathrm{O}}^{-}$
2. B.$\mathrm{Cl}{\mathrm{O}}_2^{-}$
3. C.$\mathrm{Cl}{\mathrm{O}}_3^{-}$
4. D.$\mathrm{Cl}{\mathrm{O}}_4^{-}$

Match List I with List II and select the correct answer using the code given below the Lists : $$\begin{array}{ll}\text{List I (Process)}& \text{List II (Type of change)}\\ \text{A. Heating Camphor}& \text{1. Chemical}\\ \text{B. Cooling of water vapour up to room temperature}& \text{2. Evaporation}\\ \text{C. Cooking an egg}& \text{3. Condensation}\\ \text{D. Formation of water vapour at room temperature}& \text{4. Sublimation}\end{array}$$ Code :

1. A.A-4 B-3 C-1 D-2
2. B.A-4 B-1 C-3 D-2
3. C.A-2 B-1 C-3 D-4
4. D.A-2 B-3 C-1 D-4

Which one of the following statements with regard to expansion of materials due to heating is not correct?

1. A.As ice melts, it expands uniformly up to 4°C.
2. B.Mercury thermometer works using the principle of expansion due to heating.
3. C.Small gap is kept between two rails to allow for expansion due to heating.
4. D.The length of metallic wire increases when its temperature is increased.

Which one of the following is not a form of stored energy?

1. A.Nuclear energy
2. B.Potential energy
3. C.Electrical energy
4. D.Chemical energy

Which one of the following oxides dissolves in water ?

1. A.$\mathrm{CuO}$
2. B.$\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_3$
3. C.$\mathrm{F}{\mathrm{e}}_2{\mathrm{O}}_3$
4. D.$\mathrm{N}{\mathrm{a}}_2\mathrm{O}$

Matter around us can exist in three different states, namely, solid, liquid and gas. The correct order of their compressibility is

1. A.Liquid < Gas < Solid
2. B.Solid < Liquid < Gas
3. C.Gas < Liquid < Solid
4. D.Solid < Gas < Liquid

The temperature at which a solid melts to become a liquid at the atmospheric pressure is called its melting point. The melting point of a solid is an indication of

1. A.strength of the intermolecular forces of attraction
2. B.strength of the intermolecular forces of repulsion
3. C.molecular mass
4. D.molecular size

Which one of the following elements will not react with dilute $\mathrm{HCl}$ to produce ${\mathrm{H}}_2$ ?

1. A.$\mathrm{Hg}$
2. B.$\mathrm{Al}$
3. C.$\mathrm{Mg}$
4. D.$\mathrm{Fe}$

When a solid is heated, it turns directly into a gas. This process is called

1. A.Condensation
2. B.Evaporation
3. C.Sublimation
4. D.Diffusion

Which one of the following is water gas ?

1. A.Mixture of carbon monoxide and hydrogen
2. B.Mixture of carbon monoxide and nitrogen
3. C.Mixture of carbon dioxide and water vapour
4. D.Mixture of carbon monoxide and water vapour

Suppose you have four test tubes labelled as ‘A’, ‘B’, ‘C’ and ‘D’. ‘A’ contains plain water, ‘B’ contains solution of an alkali, ‘C’ contains solution of an acid, and ‘D’ contains solution of sodium chloride. Which one of these solutions will turn phenolphthalein solution pink ?

1. A.Solution ‘A’
2. B.Solution ‘B’
3. C.Solution ‘C’
4. D.Solution ‘D’

An atom of carbon has 6 protons. Its mass number is 12. How many neutrons are present in an atom of carbon?

1. A.12
2. B.6
3. C.10
4. D.14

Which one of the following is a reduction reaction?

1. A.$2Mg(\mathrm{s})+{\mathrm{O}}_2(\mathrm{g})\to 2MgO(\mathrm{s})$
2. B.$\mathrm{S}(\mathrm{s})+{\mathrm{O}}_2(\mathrm{g})\to \mathrm{S}{\mathrm{O}}_2(\mathrm{g})$
3. C.$2HgO(\mathrm{s})\to 2Hg(l)+{\mathrm{O}}_2(\mathrm{g})$ (heat)
4. D.$\mathrm{Mg}(\mathrm{s})+\mathrm{S}(\mathrm{s})\to \mathrm{MgS}(\mathrm{s})$

Which one of the following oxides of nitrogen is known as ‘anhydride’ of nitric acid?

1. A.${\mathrm{N}}_2\mathrm{O}$
2. B.${\mathrm{N}}_2{\mathrm{O}}_3$
3. C.$\mathrm{N}{\mathrm{O}}_2$
4. D.${\mathrm{N}}_2{\mathrm{O}}_5$

Which one of the following is the chemical name for baking soda?

1. A.Sodium bicarbonate (Sodium hydrogen carbonate)
2. B.Sodium carbonate
3. C.Potassium bicarbonate (Potassium hydrogen carbonate)
4. D.Potassium carbonate

Directions: The following 05 (Five) items consist of two statements, Statement I and Statement II. Examine these two statements carefully and select the answers to these items using the code given below: Code: Statement I: Petroleum is a mixture of many different hydrocarbons of different densities. Statement II: The grade of petroleum depends mainly on the relative proportion of the different hydrocarbons.

1. A.Both the Statements are individually true and Statement II is the correct explanation of Statement I.
2. B.Both the Statements are individually true but Statement II is not the correct explanation of Statement I.
3. C.Statement I is true but Statement II is false.
4. D.Statement I is false but Statement II is true.

Which one of the following is not a chemical change?

1. A.Ripening of fruits
2. B.Curdling of milk
3. C.Freezing of water
4. D.Digestion of food

Soap is sodium or potassium salt of

1. A.Stearic acid
2. B.Oleic acid
3. C.Palmitic acid
4. D.All of the above

Which one of the following carbon compounds will not give a sooty flame?

1. A.Benzene
2. B.Hexane
3. C.Naphthalene
4. D.Anthracene

One of the main causes of air pollution in cities is emissions from vehicles like cars and trucks. Cars omit various pollutants which are bad for human health when inhaled, like 1. Nitrogen oxides ($\mathrm{N}{\mathrm{O}}_{\mathrm{x}}$) 2. Carbon monoxide ($\mathrm{CO}$) 3. Carbon dioxide ($\mathrm{C}{\mathrm{O}}_2$) 4. Benzene Which of the above pollutants are not tolerated by human beings even at very low levels?

1. A.1 and 4 only
2. B.1 and 2 only
3. C.1, 2 and 3 only
4. D.1, 2 and 4 only

In case of a compound microscope which of the following statements is / are correct? 1. The focal length of the eye piece is larger than the focal length of the objective 2. The focal length of the eye piece is smaller than the focal length of the objective 3. The image produced in a normal optical microscope is real 4. The image produced in a normal optical microscope is virtual Select the correct answer using the code given below:

1. A.1 only
2. B.1 and 4
3. C.2 and 3
4. D.2 and 4

Which one of the following statements is not correct?

1. A.Conduction can occur easily in solids, less easily in liquids but hardly at all in gases
2. B.Heat energy is carried by moving particles in a convection current
3. C.Heat energy is carried by electromagnetic waves in radiation
4. D.The temperature at which a solid changes into a liquid is called the boiling point