Rate of Reaction

Rate Of Reaction

Introduction

I will be investigating the rate of reaction, which is the amount of substance taken for the reaction. Often the rate curve is a negative correlation. As we increase the temperature, the time taken for the cross to disappear will decrease.

Other Information

The most important factors that affect the rate of reaction are:

Concentration of the acid

Time taken for the cross to disappear

Temperature

Concentration of Sodium thiosulphate

The reaction will not take place unless the particles will collide with each other. The minimum energy for reaction to work is called activation energy of the reaction.

We need to know that energy is only released when new bonds are made and this happens when old bonds are broken.

To start the reaction we will need to provide enough energy. Once the reaction has been started we don’t need to put more energy because new bods will be made and old one will be broken. When the reaction has started the molecules will react when they collide therefore break old bonds and make new bonds, this will releases energy.

If activation energy is weaker or equal to produced energy reaction will take place.

We will heat up sodium thiosulphate to a certain temperature. The bigger the temperature of the sodium thiosulphate the more particles will move and are likely to collide more frequently, this will speed up the reaction.

The factor I chose to investigate is time taken for the cross to disappear. I am aiming to answer the effect of temperature on the reaction between sodium thiosulphate and hydrochloric acid.

The graph below shows what my predicted results look like.

Temperature (oC)

I am predicting that as we increase the temperature the time taken for the cross to disappear will be decrease. If the temperature was lower then the time taken for the cross to disappear will be longer.

This will happen because:

If there are more particles in the concentration there would be more collision. If there was more collision between particles then more energy will be produced therefore the temperature will increase and the cross will disappear quicker.

Variables

Dependant Variables (The one I will not change):

Time taken for the cross to disappear: If it takes longer for the cross to disappear then it means there is less collision taking place.

Less collision takes place when the temperature is not high enough.

Independent variables (the one I will change):

Temperature: If the temperature is high then there will be more collision therefore more energy will be released. If the temperature is low then it would take longer for the cross to disappear.

Controlled Variables:

Concentration of sodium thiosulphate and hydrochloric acid: : if we