The effect of varying temperature on the reaction rate and reaction sustainability between two solutions of sodium thiosulphate and hydrochloric acid can be explained using the collision theory and the Arrhenius equation.The reaction between sodium thiosulphate Na2S2O3 and hydrochloric acid HCl is as follows:Na2S2O3 aq + 2HCl aq 2NaCl aq + SO2 g + S s + H2O l 1. Reaction rate: The reaction rate is directly related to the temperature of the reacting solutions. As the temperature increases, the kinetic energy of the molecules also increases. This leads to more frequent and energetic collisions between the reactant molecules, resulting in a higher reaction rate.According to the Arrhenius equation, the reaction rate constant k is related to the temperature T by the following equation:k = Ae^-Ea/RT where A is the pre-exponential factor, Ea is the activation energy, R is the gas constant, and T is the temperature in Kelvin. As the temperature increases, the exponential term becomes larger, leading to an increase in the reaction rate constant and thus a faster reaction rate.2. Reaction sustainability: The sustainability of a reaction refers to its ability to proceed without significant loss of reactants or products. In the case of the sodium thiosulphate and hydrochloric acid reaction, the formation of a solid sulfur precipitate S can be used as an indicator of reaction sustainability. As the temperature increases, the solubility of sulfur decreases, causing it to precipitate out of the solution more quickly. This may lead to a decrease in reaction sustainability at higher temperatures, as the sulfur precipitate can hinder the contact between the reactant molecules.In summary, increasing the temperature of the reaction between sodium thiosulphate and hydrochloric acid will generally lead to a faster reaction rate due to increased molecular collisions and kinetic energy. However, the reaction sustainability may be negatively affected at higher temperatures due to the decreased solubility of sulfur and the formation of a solid precipitate that can hinder the reaction.