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Monday, May 2, 2011

6.2.4




Predict and explain using the collision theory, the qualitative effects of particles size, temperature, concentration and pressure on the rate of reaction. 


1. Temperature
As temperature increases, the rate of reaction also increases. This is because increases in temperature causes the increase in kinetic energy, thus increasing the energy in particles, causing them to collide into each other more quickly.

The area under both of the graphs are the same. However, the rate of reaction and the time taken varies. The peak of the curve shifts to the right, the higher the temperature, the more the energy, and the higher the activation energy. 

2. Concentration
The higher the concentration, the more the particles present in the same area. Therefore there will be a higher chance in which the particles will bump into each other. 

3. Particles size
Decreasing the particle size, increases the chances of collision. The smaller the size of the particle, the higher the surface area, and the chances for it to get into contact with another particle. 

4. Pressure
For objects in the gaseous state, by increasing the pressure, the collision increases. This because, increase in pressure, causes the gas to compress, this results in the higher concentration of gas. Allow more collision between particles, increasing the rate of reaction. 

An experiment was carried out using the different sizes of marble chips in acid. 

Independent variables: the size of the marble chips 
Dependent variables: Time taken for the reaction to complete
Controlled variables: temperature, concentration of acid, pressure of surrounding


The amount of time taken for the rate of reaction varies between the different marble chips, due to the difference in the particle sizes and surface area. 


1 comment:

  1. 6.2.4 Good work Su-May. I would like to see the answers to these questions though:
    4. Using collision theory explain the following the shape of the graphs at the start of the reaction
    5. What does the gradient of the graph at any one point represent?
    6. What are the units for the gradient of the graph?
    7. Discuss the reasons for the differences in the shape of the graphs

    I think the shape of the graphs look strange also - can you check with another student's blog what they should look like - thanks

    ReplyDelete