Chemistry · NDA previous year questions

Molecules of which of the following has cage like structure ? 1. Diamond 2. Graphite 3. Fullerenes Select the correct answer using the code given below :

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

Temporary hardness in water is due to which one of the following of Calcium and Magnesium ?

1. A.Hydrogencarbonates
2. B.Carbonates
3. C.Chlorides
4. D.Sulphates

Which one of the following elements is least reactive with water ?

1. A.Lithium
2. B.Sodium
3. C.Potassium
4. D.Cesium

Rutherford's alpha-particle scattering experiment was responsible for the discovery of

1. A.Electron
2. B.Proton
3. C.Nucleus
4. D.Helium

Which one of the following statements is NOT correct ?

1. A.In the conduction mode of transference of heat, the molecules of solid pass heat from one molecule to another without moving from their positions
2. B.The amount of heat required to raise the temperature of a substance is called its specific heat capacity
3. C.The process of heat transfer in liquids and gases is through convection mode
4. D.The process of heat transfer from a body at higher temperature to a body at lower temperature without heating the space between them is known as radiation

The amount of heat required to change a liquid to gaseous state without any change in temperature is known as

1. A.specific heat capacity
2. B.mechanical equivalent of heat
3. C.latent heat of vaporization
4. D.quenching

Which one of the following elements forms highest number of compounds ?

1. A.Oxygen
2. B.Hydrogen
3. C.Chlorine
4. D.Carbon

Which one of the following elements corrodes rapidly ?

1. A.Aluminium
2. B.Iron
3. C.Zinc
4. D.Silver

20 g of common salt is dissolved in 180 g of water. What is the mass percentage of the salt in the solution ?

1. A.5%
2. B.9%
3. C.10%
4. D.15%

The valency of an element depends upon the

1. A.total number of protons in an atom
2. B.mass number of an atom
3. C.total number of neutrons in an atom
4. D.total number of electrons in the outer most shell of an atom

Match List I with List II and select the correct answer using the code given below the Lists : | List I (Noble gas) | List II (Use) | | :--- | :--- | | A. Argon | 1. In lights for advertising display | | B. Neon | 2. Airport landing lights and in light houses | | C. Krypton | 3. Light in photographer's flash gun | | D. Xenon | 4. In tungsten filament to last longer | Code : A B C D

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

Radon is

1. A.an inert gas
2. B.an artificial fibre
3. C.an explosive
4. D.a metal

Which one of the following elements is used in pencil-lead?

1. A.Zinc
2. B.Lead
3. C.Carbon (Graphite)
4. D.Tin

Stung by hairs of nettle leaves causes burning pain. This is due to the injection of

1. A.Acetic acid
2. B.Methanoic acid
3. C.Sulphuric acid
4. D.Hydrochloric acid

The chemical name of baking soda is

1. A.$\mathrm{N}{\mathrm{a}}_2\mathrm{C}{\mathrm{O}}_3$
2. B.$\mathrm{NaHC}{\mathrm{O}}_3$
3. C.$\mathrm{CaC}{\mathrm{O}}_3$
4. D.$\mathrm{NaOH}$

The property of electric current which is applicable in the fuse wire is

1. A.chemical effect of current
2. B.magnetic effect of current
3. C.heating effect of current
4. D.optical property of current

If we plot a graph between volume $V$ and inverse of pressure $P$ (i.e., $\frac{1}{P}$) for an ideal gas at constant temperature $T$, the curve so obtained is

1. A.straight line
2. B.circle
3. C.parabola
4. D.hyperbola

Which one of the following statements is not correct ?

1. A.The SI unit of charge is ampere-second
2. B.Debye is the unit of dipole moment
3. C.Resistivity of a wire of length $l$ and area of cross-section $a$ depends upon both $l$ and $a$
4. D.The kinetic energy of an electron of mass $m$ kg and charge $e$ coulomb, when accelerated through a potential difference of $V$ volt, is $eV$ joule

Which of the following items is used in the household wirings to prevent accidental fire in case of short circuit?

1. A.Insulated wire
2. B.Plastic switches
3. C.Non-metallic coatings on conducting wires
4. D.Electric fuse

Match List I with List II and select the correct answer using the code given below the Lists: $$\begin{array}{ll}\text{List I (Element)}& \text{List II (Highest Valency)}\\ \text{A. Sulfur}& \text{1. Five}\\ \text{B. Phosphorous}& \text{2. Six}\\ \text{C. Lead}& \text{3. Two}\\ \text{D. Silver}& \text{4. Four}\end{array}$$ Code : $$\begin{array}{cccc}\text{A}& \text{B}& \text{C}& \text{D}\end{array}$$

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

Identify the element having zero valency

1. A.Sulphur
2. B.Phosphorous
3. C.Lead
4. D.Radon

There are six electrons, six protons and six neutrons in an atom of an element. What is the atomic number of the element?

1. A.6
2. B.12
3. C.18
4. D.24

Which one of the following has different number of molecules? (All are kept at normal temperature and pressure)

1. A.3 gram of Hydrogen
2. B.48 gram of Oxygen
3. C.42 gram of Nitrogen
4. D.2 gram of Carbon

Which one of the following statements is correct?

1. A.Covalent bonds are directional
2. B.Ionic bonds are directional
3. C.Both covalent and ionic bonds are directional
4. D.Both covalent and ionic bonds are non-directional

The LPG cooking gas contains propane and butane as the constituents. A sulfur containing compound is added to the LPG, because

1. A.it lowers the cost of production
2. B.it enhances the efficiency of LPG
3. C.it facilitates easy detection of leakage of the gas
4. D.it assists in liquefying hydrocarbons