This experiment is to investigate the rate of reaction between Sodium Thiosulphate and Hydrochloric acid. The equation for this reaction is:
Na2S2O3 (aq) + 2HCl (aq) 2NaCl (aq) + S (s) + H2O (L) + SO2 (g)
Sodium + Hydrochloric Sodium + Sulphur + Water + Sulphur
Thiosulphate Acid Chloride Oxide
I predict that the higher the concentration of acid, the quicker the reaction. The higher the concentration, the more particles in the acid, which makes more of a chance that the particles will collide – so more chance of a reaction taking place.