How Temperature Affects Reaction Rate

Lab Report: How Temperature affects Reaction Rate

Aim:

The Aim is to investigate how temperature can affect Reaction Rate. The experiment will be performed by heating equally sized and weighted lime stones with equal amounts and concentration of Hydrochloric acid at different temperatures. The temperatures will be 35˚C and 40˚C. We will measure the reaction rates by observing gas release of the reaction between lime stones and Hydrochloric acid. The amount of gas release at different temperatures will be compared afterwards to see if temperature can affect Reaction Rate.

Hypothesis:

I predict that the higher the temperature, the higher the Reaction Rate will be. Therefore I predict that the Reaction rate of the 40˚ C heated Lime Stones and HCL acid will be higher than the 35˚ C heated Lime Stones and HCL acid. I predict this because I know that when the temperature is raised, particles move faster and collide more frequently. Therefore if temperature is raised, the Reaction rate will increase. The increase in temperature will allow Reaction rate to rise and also increase amount of molecules being thermally activated (give enough energy to collide). I also predict that Reaction rate will increase roughly by a double for each 10˚ C. In this case, I suppose the Reaction rate will increase roughly by a half for 5˚C increased temperature.

Variables:

The independent variable is the one that is changed by the scientist:

 Temperature in ˚C, at which the HCl acid and Lime Stones will be heated

The dependent variable changes in response to the change the scientist makes to the independent variable:

 Rate of Reaction, measured by observing how much gas (in cmÑ-) is produced

 Amount of molecules activated (given enough energy to collide)

 How fast the particles move

 How energetic the molecules will collide

The controlled variables are quantities that a scientist wants to remain constant:

 Size of Lime Stones

 Amount of Lime Stones

 Amount of Hydrochloric Acid

 Concentration of Hydrochloric Acid

Apparatus:

 Tripod

 Gauze

 Bunsen Burner

 2x Flasks (100 cmÑ-)

 Delivery Tube

 Stand and Clamp

 Gas Syringe (100 cmÑ-)

 2x 20g Lime stones (small pieces)

 2x 20cmÑ- of 0.2M Hydrochloric Acid (HCl)

 Thermometer (capable to measure until 100˚ C)

 Stop watch

 Access to balance

 Eye Protection

 Bung

Diagram:

Method:

1. Collect the apparatus, as listed in the 'Apparatus' list

2. Set up Apparatus as shown in the diagram. The Apparatus should be set up without the bung, delivery tube and the gas syringe at first as they are not required until later on in the experiment.

3. Heat the flask with 20 cmÑ- Hydrochloric acid until it reaches the temperature of 35˚C

4. Turn off heat immediately and take the thermometer out of the flask

5. Place the 20g of Lime Stone in the flask and immediately block the top of the flask with bung. The bung must be connected to the delivery tube, which will be connected to the Gas Syringe (as shown in diagram).

6. Record the results/Reaction Rate by observing the amount of gas produced each 15 seconds (in regular intervals).

7. Keep recording until no more reaction can be seen.

8. Repeat

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