Effect of temperature on rate of reaction experiment sodium thiosulphate and hydrochloric acid

Title: The Effect Temperature of Sodium Thiosulfate Has On The Rate of Reaction with Hydrochloric Acid Statement of Inquiry: What is the effect of changing a factor on the rate of chemical reaction?

Aim: The aim of this experiment is to observe how by increasing the temperature of sodium thiosulfate in a solution with 2.0 molar Hydrochloric acid can affect the rate of reaction and the rate in which a precipitate is formed.

Hypothesis: If the temperature of the sodium thiosulfate is increased, then the time it takes the precipitate to form will decrease therefore leading to the rate of reaction to increase as well. This can be explained as the temperature increases, the particles in the molecule will be moving more rapidly and hence as they move quicker, they will be colliding with other particles more frequently and with more energy. This energy will likely overcome the activation energy barrier and break the initial bonds and therefore produce a successful reaction and due to the increase in frequency of collisions, the time it takes the precipitate to form will decrease and since the product/precipitate is produced faster, therefore the rate of reaction will increase. Balanced chemical equation of what will happen: Na2S2O3 + 2HCl = 2NaCl + S + H2O+ SO2 Word Equation: sodium thiosulphate + hydrochloric acid = sodium chloride (salt) + sulphur + water + sulphur dioxide Independent Variables: ❖ Increase in temperature of sodium thiosulfate 1) 40 degrees

2) 50

Investigate the effect of temperature on the rate of reaction between sodium thiosulfate and hydrochloric acid to better understand basic collision theory

In this experiment the effect of temperature on the rate of reaction between sodium thiosulfate and hydrochloric acid is investigated.

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Theory
The rate of a chemical reaction depends to a great extent upon temperature. The rate of reaction increases with increase in temperature. Increase in temperature increases kinetic energy of the molecules. Therefore, the fraction of molecules having energy greater than its threshold energy increases which results in the increase in number of effective collisions per second. It has been observed that in most of the cases for every 10°C rise in temperature, the rate of the reaction becomes almost double. The rate of reaction between sodium thiosulphate and hydrochloric acid also increases with increase in temperature.

Apparatus
Conical flask (250 ml), measuring cylinders (50 ml and 5 ml), stop-watch, thermometer, tripod stand, wire-gauze and burner.

Materials Required
0.1 M Na2S203 solution, 1 M HCl, distilled water and cone. HN03.

Procedure

Take 50 ml of 0.1 M Na2S203 solution in a 100 ml conical flask and note its temperature with the help of a thermometer.
Add 10 ml of 1 M HCl to it and start the stop-watch immediately when half of the hydrochloric acid solution has been added.
Shake the contents of the flask gently and place it on the tile with a cross-mark as shown in Fig.
Observe the cross-mark from the top and note the time taken for the mark to become just invisible.
Empty the flask and clean it thoroughly with cone. HN03 and then with water.
Take again 50 ml of 0.1 M Na2S203 in conical flask and heat it so that the temperature of the solution becomes (T + 10°)C.
Remove the flask from the tripod-stand and add 10 ml of 1 M HCl to it and start the stop-watch.
Shake the contents gently and place it on the tile having a cross-mark.
Note the time taken for the mark to become just invisible.
Repeat the experiment at (T + 20)°C, (T + 30)°C and (T + 40)°C temperatures and record the observations as given below.

Observations
Volume of 0.1 M Na2S203 solution taken each time = 50 ml Volume of 1 M HCl added each time = 10 ml.