rate of reaction between sodium thiosulphate and hydrochloric acid

Authors Avatar


Aim: To investigate the rate of reaction between a fixed amount of sodium Thiosulphate and different concentrations of hydrochloric acid.


The factors affecting the  rate of reaction are –

  • Surface area of the reactants
  • Concentration of the reactants
  • Temperature at which the reaction occurs
  • Light  
  • Use of catalyst

The definition of collision theory as stated in www.wikipedia.org             ‘the collision theory assumes that for a reaction to occur the reactant particles must collide, but only a certain fraction of the total collisions, which are called effective collisions, cause the transformation of reactant molecules into products. This is due to the fact that only a fraction of the molecules have sufficient energy and the right orientation at the moment of impact to break the existing bonds and form new bonds. The minimal amount of energy needed so that the molecule is transformed is called activation energy’

Therefore an increase in the concentration of the reactants would increase the chances of collision between particles which is also called the collision frequency. Therefore we can say that the effective collision frequency also increases and thus increases the rate of reaction.

Join now!



  • The concentrations of hydrochloric acid.
  • Volume of water
  • Volume of Hydrochloric acid



  • Time taken for the cross to disappear.
  • Colour change of the sodium Thiosulphate and hydrochloric acid.
  • Change in temperature after the reaction is over.


  • Volume of hydrochloric acid used.
  • Volume of sodium Thiosulphate used.
  • Concentration of sodium Thiosulphate
  • Surroundings
  • Room temperature

Molar calculations to calculate the concentration of HCl after diluting it with water:

The molar value of HCl in a ...

This is a preview of the whole essay