English Medium Class 10 - CBSE Question Bank Solutions for Science

Which of the following is not a physical change?

The following reaction is an example of a `4"NH"_3("g") + "SO"_2 -> 4"NO"("g") + 6"H"_2"O"("g")`

1. displacement reaction
2. combination reaction
3.  redox reaction
4. neutralisation reaction

Which of the following statements about the given reaction are correct?

`3"Fe"("s") + 4"H"_2"O"("g") -> "Fe"_3"O"_4("s") + 4"H"_2("g")`

1.  Iron metal is getting oxidised
2. Water is getting reduced
3. Water is acting as reducing agent
4.  Water is acting as oxidising agent

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)

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.

A dilute ferrous sulphate solution is 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?

Which among the following is(are) double displacement reaction(s)?

1. `"Pb" + "CuCl"_2 -> "PbCl"_2 + "Cu"`
2. `"Na"_2"SO"_4 + "BaCl"_2 -> "BaSO"_4 + 2"NaCl"`
3. `"C" + "O"_2 -> "CO"_2`
4. `"CH"_4 + 2"O"_2 -> "CO"_2 + 2"H"_2"O"`

Which among the following statement(s) is(are) true? ‘Exposure of silver chloride to sunlight for a long duration turns grey due to

1. The formation of silver by the decomposition of silver chloride.
2. sublimation of silver chloride.
3. decomposition of chlorine gas from silver chloride.
4. oxidation of silver chloride.

Give the characteristic tests for the following gases :

1. CO₂
2. SO₂
3. O₂
4. H₂

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

Although metals form basic oxides, which of the following metals form an amphoteric oxide?

A molecule of ammonia (NH₃) has

Which of the following are correct structural isomers of butane?

1. \[\begin{array}{cc}
   \ce{H}\phantom{...}\ce{H}\phantom{...}\ce{H}\phantom{...}\ce{H}\\
   |\phantom{....}|\phantom{....}|\phantom{....}|\\
   \ce{H - C - C - C - C - H}\\
   |\phantom{....}|\phantom{....}|\phantom{....}|\\
   \ce{H}\phantom{...}\ce{H}\phantom{...}\ce{H}\phantom{...}\ce{H}\\
   \end{array}\]
   
   
2. \[\begin{array}{cc}
   \ce{H}\phantom{...}\ce{H}\phantom{...}\ce{H}\\
   |\phantom{....}|\phantom{....}|\\
   \ce{H - C - C - C - H}\\
   |\phantom{.....}|\phantom{.....}|\\
   \ce{H}\ce{H-C-H}\ce{H}\\
   |\\
   \ce{H}\\
   \end{array}\]
3. \[\begin{array}{cc}
   \ce{H}\phantom{...}\ce{H}\phantom{...}\ce{H}\\
   |\phantom{....}|\phantom{....}|\\
   \ce{H - C - C - C - H}\\
   |\phantom{.....}\backslash\phantom{..}|\\
   \phantom{....}\ce{H}\phantom{......}\ce{C - H}\phantom{}\\
   \phantom{.......}|\\
   \phantom{.......}\ce{H}\\
   \end{array}\]
4. \[\begin{array}{cc}
   \ce{H}\phantom{...}\ce{H}\\
   |\phantom{....}|\\
   \ce{H - C - C - H}\\
   |\phantom{....}|\\
   \ce{H - C - C - H}\\
   |\phantom{....}|\\
   \ce{H}\phantom{...}\ce{H}\\
   \end{array}\]

`"CH"_3 - "CH"_2 - "OH" overset("Alkaline""KMnO"_4 + "Heat")(->) "CH"_3 - "COOH"`

In the above given reaction, alkaline KMnO₄ acts as 

Oils on treating with hydrogen in the presence of palladium or nickel catalyst form fats. This is an example of

The correct structural formula of butanoic acid is

Mineral acids are stronger acids than carboxylic acids because

1. mineral acids are completely ionised
2. carboxylic acids are completely ionised
3. mineral acids are partially ionised
4. carboxylic acids are partially ionised

Carbon forms four covalent bonds by sharing its four valence electrons with four univalent atoms, e.g. hydrogen. After the formation of four bonds, carbon attains the electronic configuration of

Electrical impulse travels in a neuron from

In a synapse, the chemical signal is transmitted from ______.