General Science

An element A is soft and can be cut with a knife. This is very reactive to air and cannot be kept open in air. It reacts vigorously with water. Identify the element from the following 

  1. Mg
  2. Na
  3. P
  4. Ca

2 mL each of concentrated HCl, HNO3 and a mixture of concentrated HCl and concentrated HNO3 in the ratio of 3 : 1 were taken in test tubes labelled as A, B and C. A small piece of metal was put in each test tube. No change occurred in test tubes A and B but the metal got dissolved in test tube C respectively. The metal could be

  1. Al
  2. Au
  3. Cu
  4. Pt

If copper is kept open in air, it slowly loses its shining brown surface and gains a green coating. It is due to the formation of

  1. CuSO4
  2. CuCO3
  3. Cu(NO3)2
  4. CuO

Stainless steel is very useful material for our life. In stainless steel, iron is mixed with

  1. Ni and Cr
  2. Cu and Cr
  3. Ni and Cu
  4. Cu and Au

Galvanisation is a method of protecting iron from rusting by coating with a thin layer of

  1. Gallium
  2. Aluminium
  3. Zinc
  4. Silver

Silver articles become black on prolonged exposure to air. This is due to the formation of

  1. Ag3N
  2. Ag2O
  3. Ag2S
  4. Ag2S and Ag3N

Which of the following metals exist in their native state in nature?

  1. Cu
  2. Au
  3. Zn
  4. Ag

Select the correct option:

  1. (i) and (ii)
  2. (ii) and (iii)
  3. (ii) and (iv)
  4. (iii) and (iv)

Which one of the following properties is not generally exhibited by ionic compounds?

  1. Solubility in water
  2. Electrical conductivity in solid state
  3. High melting and boiling points
  4. Electrical conductivity in molten state

What happens when calcium is treated with water?

  1. It does not react with water
  2. It reacts violently with water
  3. It reacts less violently with water
  4. Bubbles of hydrogen gas formed stick to the surface of calcium

Select the correct option:

  1. (i) and (iv)
  2. (ii) and (iii)
  3. (i) and (ii)
  4. (iii) and (iv)

Which one of the following metals do not react with cold as well as hot water?

  1. Na
  2. Ca
  3. Mg
  4. Fe

The ability of metals to be drawn into thin wire is known as

  1. ductility
  2. malleability
  3. sonorousity
  4. conductivity

Identify the correct representation of reaction occurring during chloralkali process

  1. 2NaCl(l) + 2H2O(l) → 2NaOH(l) + Cl2(g) + H2(g)
  2. 2NaCl(aq) + 2H2O(aq) → 2NaOH(aq) + Cl2(g) + H2(g)
  3. 2NaCl(aq) + 2H2O(l) → 2NaOH(aq) + Cl2(aq) + H2(aq)
  4. 2NaCl (aq) + 2H2O (l) → 2NaOH(aq) + Cl2(g) + H2(g)

Which of the following is not a mineral acid?

  1. Hydrochloric acid
  2. Citric acid
  3. Sulphuric acid
  4. Nitric acid

Which of the following is used for dissolution of gold?

  1. Hydrochloric acid
  2. Sulphuric acid
  3. Nitric acid
  4. Aqua regia

The pH of the gastric juices released during digestion is

  1. less than 7
  2. more than 7
  3. equal to 7
  4. equal to 0

One of the constituents of baking powder is sodium hydrogen carbonate, the other constituent is

  1. hydrochloric acid
  2. tartaric acid
  3. acetic acid
  4. sulphuric acid

Common salt besides being used in kitchen can also be used as the raw material for making

  1. washing soda
  2. bleaching powder
  3. baking soda
  4. slaked lime

Select the correct option:

  1. (i) and (ii)
  2. (i), (ii) and (iv)
  3. (i) and (iii)
  4. (i), (iii) and (iv)

Sodium hydrogen carbonate when added to acetic acid evolves a gas. Which of the following statements are true about the gas evolved?

  1. It turns lime water milky
  2. It extinguishes a burning splinter
  3. It dissolves in a solution of sodium hydroxide
  4. It has a pungent odour

Select the correct option:

  1. (i) and (ii)
  2. (i), (ii) and (iii)
  3. (ii), (iii) and (iv)
  4. (i) and (iv)

Which of the following gives the correct increasing order of acidic strength?

  1. Water < Acetic acid < Hydrochloric acid
  2. Water < Hydrochloric acid < Acetic acid
  3. Acetic acid < Water < Hydrochloric acid
  4. Hydrochloric acid < Water < Acetic acid

A sample of soil is mixed with water and allowed to settle. The clear supernatant solution turns the pH paper yellowish-orange. Which of the following would change the colour of this pH paper to greenish-blue?

  1. Lemon juice
  2. Vinegar
  3. Common salt
  4. An antacid

Calcium phosphate is present in tooth enamel. Its nature is

  1. basic
  2. acidic
  3. neutral
  4. amphoteric

Which of the following salts does not contain water of crystallisation?

  1. Blue vitriol
  2. Baking soda
  3. Washing soda
  4. Gypsum

During the preparation of hydrogen chloride gas on a humid day, the gas is usually passed through the guard tube containing calcium chloride. The role of calcium chloride taken in the guard tube is to

  1. absorb the evolved gas
  2. moisten the gas
  3. absorb moisture from the gas
  4. absorb Cl ions from the evolved gas

An aqueous solution turns red litmus solution blue. Excess addition of which of the following solution would reverse the change?

  1. Baking powder
  2. Lime
  3. Ammonium hydroxide solution
  4. Hydrochloric acid

What happens when a solution of an acid is mixed with a solution of a base in a test tube?

  1. The temperature of the solution increases
  2. The temperature of the solution decreases
  3. The temperature of the solution remains the same
  4. Salt formation takes place

Select the correct option:

  1. (i) only
  2. (i) and (iii)
  3. (ii) and (iii)
  4. (i) and (iv)

Electrolysis of water is a decomposition reaction. The mole ratio of hydrogen and oxygen gases liberated during electrolysis of water is

  1. 1:1
  2. 2:1
  3. 4:1
  4. 1:2

Barium chloride on reacting with ammonium sulphate forms barium sulphate and ammonium chloride. Which of the following correctly represents the type of the reaction involved?

  1. Displacement reaction
  2. Precipitation reaction
  3. Combination reaction
  4. Double displacement reaction

Select the correct option:

  1. (i) only
  2. (ii) only
  3. (iv) only
  4. (ii) and (iv)

A dilute ferrous sulphate solution was gradually added to the beaker containing acidified permanganate solution. The light purple colour of the solution fades and finally disappears. Which of the following is the correct explanation for the observation?

  1. KMnO4 is an oxidising agent, it oxidises FeSO4
  2. FeSO4 acts as an oxidising agent and oxidises KMnO4
  3. The colour disappears due to dilution; no reaction is involved
  4. KMnO4 is an unstable compound and decomposes in presence of FeSO4 to a colourless compound.

Three beakers labelled as A, B and C each containing 25 mL of water were taken. A small amount of NaOH, anhydrous CuSO4 and NaCl were added to the beakers A, B and C respectively. It was observed that there was an increase in the temperature of the solutions contained in beakers A and B, whereas in case of beaker C, the temperature of the solution falls. Which one of the following statement(s) is (are) correct?

  1. In beakers A and B, exothermic process has occurred.
  2. In beakers A and B, endothermic process has occurred.
  3. In beaker C exothermic process has occurred.
  4. In beaker C endothermic process has occurred.

Select the correct option:

  1. (i) only
  2. (ii) only
  3. (i) and (iv)
  4. (ii) and (iii)

Which of the following are exothermic processes?

  1. Reaction of water with quick lime
  2. Dilution of an acid
  3.  Evaporation of water
  4. Sublimation of camphor (crystals)

Select the correct option:

  1. (i) and (ii)
  2. (ii) and (iii)
  3. (i) and (iv)
  4. (iii) and (iv)

Which of the following is not a physical change?

  1. Boiling of water to give water vapour
  2. Melting of ice to give water
  3. Dissolution of salt in water
  4. Combustion of Liquefied Petroleum Gas (LPG)

‘Ozone-hole’ means

  1. a large sized hole in the ozone layer
  2. thinning of the ozone layer
  3. small holes scattered in the ozone layer
  4. thickening of ozone in the ozone layer

Which of the following is not a green house gas?

  1. nitrogen gas
  2. water vapour
  3. methane gas
  4. carbon dioxide

The process of nitrogen-fixation by bacteria does not take place in the presence of

  1. molecular form of hydrogen
  2. elemental form of oxygen
  3. water
  4. elemental form of nitrogen

The two forms of oxygen found in the atmosphere are

  1. water and ozone
  2. water and oxygen
  3. ozone and oxygen
  4. water and carbon-dioxide

If there were no atmosphere around the earth, the temperature of the earth will

  1. increase
  2. go on decreasing
  3. increase during day and decrease during night
  4. be unaffected

The atmosphere of the earth is heated by radiations which are mainly

  1. radiated by the sun
  2. re-radiated by land
  3. re-radiated by water
  4. re-radiated by land and water

Which one of the following causes kala-azar?

  1. Ascaris
  2. Trypanosoma
  3. Leishmania
  4. Bacteria

Which one of the following diseases is caused by protozoans?

  1. Malaria
  2. Influenza
  3. AIDS
  4. Cholera

Which one of the following disease is not transmitted by mosquito?

  1. Brain fever
  2. Malaria
  3. Typhoid
  4. Dengue

Which one of the following is not a bacterial disease

  1. Cholera
  2. Tuberculosis
  3. Anthrax
  4. Influenza

Which one of the following is not a viral disease?

  1. Dengue
  2. AIDS
  3. Typhoid
  4. Influenza

Sound travels in air if

  1. particles of medium travel from one place to another
  2. there is no moisture in the atmosphere
  3. disturbance moves
  4. both particles as well as disturbance travel from one place to another

A body is falling from a height h. After it has fallen a height h/2, it will possess

  1. only potential energy
  2. only kinetic energy
  3. half potential and half kinetic energy
  4. more kinetic and less potential energy

The work done on an object does not depend upon the

  1. displacement
  2. force applied
  3. angle between force and displacement
  4. initial velocity of the object

An iron sphere of mass 10 kg has the same diameter as an aluminium sphere of mass is 3.5 kg. Both spheres are dropped simultaneously from a tower. When they are 10 m above the ground, they have the same

  1. acceleration
  2. momenta
  3. potential energy
  4. kinetic energy

In case of negative work the angle between the force and displacement is

  1. 45°
  2. 90°
  3. 180°

A car is accelerated on a levelled road and attains a velocity 4 times of its initial velocity. In this process the potential energy of the car

  1. does not change
  2. becomes twice to that of initial
  3. becomes 4 times that of initial
  4. becomes 16 times that of initial

When a body falls freely towards the earth, then its total energy

  1. increases
  2. decreases
  3. remains constant
  4. first increases and then decreases

An object weighs 10 N in air. When immersed fully in water, it weighs only 8 N. The weight of the liquid displaced by the object will be

  1. 2 N
  2. 8 N
  3. 10 N
  4. 12 N

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