10th Standard CBSE - Science - Chemical Reactions and Equations

Buy 10th Science MCQ Online Test CBSE Practice test pack

Question - 1

Which of the following statements about the reaction below are incorrect?
2PbO(s) + C(s) \(\rightarrow\) 2Pb(s) + CO2(s)
(a) Lead is getting reduced        (b) Carbon dioxide is getting oxidized
(c) Carbon is getting oxidized     (d) Lead oxide is getting reduced.

  • A (a) and (b)
  • B (a) and (c)
  • C (a), (b) and (c)
  • D All of these

Question - 2

Fe2O3 + 2Al \(\rightarrow\) Al2O3 + 2Fe. The reaction is an example of a 

  • A Combination of reaction
  • B Double displacement reaction
  • C Decomposition reaction
  • D Displacement reaction.

Question - 3

What happens when dilute hydrochloride acid is added to iron fillings? Tick the correct answer.

  • A Hydrogen gas and Iron chloride are produced.
  • B Chloride gas and Iron hydroxide are produced.
  • C No reaction takes place
  • D Iron salt and water are produced

Question - 4

Which of the following is not a physical change?

  • A Boiling of water to give water vapour.
  • B Melting of ice to give water.
  • C Dissolution of salt in water.
  • D Combustion of Liquefied Petroleum Gas(LPG).

Question - 5

The following reaction: 4NH3(g) + 5O2(g) \(\rightarrow\) 4NO(g) + 6H2O(g) is an example of a 
(i) displacement reaction
(ii) combination reaction
(iii) redox reaction
​​​​​​​(iv) neutralisation reaction

  • A (i) and (iv)
  • B (ii) and (iii)
  • C (i) and (iii)
  • D (iii) and (iv)

Question - 6

Which of the following statements about the given reaction are correct?
3Fe(s) + 4H2O(g) \(\rightarrow\) Fe3O4(s) + 4H2(g)
(i) Iron metal is getting oxidised
(ii) Water is getting reduced
(iii) Water is acting as reducing agent
(iv) Water is acting as oxidising agent

  • A (i), (ii) and (iii)
  • B (iii) and (iv)
  • C (i), (ii) and (iv)
  • D (ii) and (iv)

Question - 7

Which of the following are exothermic processes?
(i) Reaction of water with quicklime
(ii) Dilution of an acid
(iii) Evaporation of water
(iv) Sublimation of camphor(crystals)

  • A (i) and (ii)
  • B (ii) and (iii)
  • C (i) and (iv)
  • D (iii) and (iv)

Question - 8

Three beakers labelled as A, B and C each containing 25 mL of water was 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?
(i) In beakers A and B, exothermic process has occurred.
(ii) In beakers A and B, endothermic process has occurred.
(iii) In beaker C exothermic process has occurred.
(iv) In beaker C endothermic process has occured.

  • A (i) only
  • B (ii) only
  • C (i) and (iv)
  • D (ii) and (iii)

Question - 9

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?

  • A KMnO4 is an oxidising agent, it oxidises FeSO4
  • B FeSO4 acts as an oxidising agent and oxidises KMnO4
  • C The colour disappears due to dilution; no reaction is involved
  • D KMnO4 is an unstable compound and decomposes in presence of FeSO4 to a colourless compound.

Question - 10

Which among the following is /are double displacement reaction(s) ?
(i) Pb + CuCl2 \(\rightarrow\) PbCl2 + Cu
(ii) Na2SO4 + BaCl2 \(\rightarrow\) BaSO4 + 2NaCl
(iii) C + O2 \(\rightarrow\) CO2
(iv) CH4 + 2O2 \(\rightarrow\) CO2 + 2H2O

  • A (i) and (iv)
  • B (ii) only
  • C (i) and (ii)
  • D (iii) and (iv)