Science

Experiment 1     Investigating the effects of temperature on reaction rates

Aim: I want to investigate hoe temperature effects the reaction rate.

Equipment:

• Conical Flask
• Beaker
• Measuring Cylinder
• Stopwatch
• Black cross on paper 
• Water Bath 
• Thermometer
• 0.1mol/L sodium thiosulfate 
• 1.0mol/L hydrochloric acid ( HCL ) 

Method: 

1. Put X on paper on the bench mat, and put the conical flask on top of paper 
2. Measure 50 ml of sodium thiosulfate solution and put it into beaker. 
3. Record the temperature of the sodium thiosulfate.
4. Measure 5 ml of HCL and pour this into the conical flask. 
5. Pour the thiosulfate into the conical flask start the stopwatch and swirl the flask, time how long it takes for the cross to disappear when viewed from above i.e look down from the mouth of the  conical flask.
6. Wash flask thoroughly.
7. Repeat the experiment using a water bath to heat the sodium thiosulfate to 30 degrees 40 degrees and 50 degrees keep the volume of acid the same each time. 

Results 

• room temp 28 seconds 
• 30 degrees 50 seconds 
• 40 degrees 19 seconds 
• 50 degrees 18 seconds 

Conclusion: A chemical reaction is when two reactants collide, they have to collide with enough force to and the correct orientation. As we made the temperature hotter it gave the reactants more kinetic energy so they moved faster. The faster the reactants move the higher chance of a successful reaction to occur in a lesser time. 

Experiment 2  Investigating the effect of concentration on reaction rate

Aim: I want to investigate hoe concentration effects the reaction rate.

Equipment: 

• A conical flask 
• measuring cylinder 
• stopwatch
• black cross on paper 
• 0.2mol/l sodium thiosulfate 
• 1.0mol/l of hydrochloric acid 

Method: Put the piece of paper with the X on the bench and put the conical flask on it.

1. Measure 10mL of Sodium Thiosulfate and put it into the conical flask.
2. Measure 40mL of Water and put it into the conical flask. Swirl to mix.
3. Measure 5mL of HCl.
4. Pour the Sodium Thiosulfate into the conical flask, start the timer and swirl the flask.
5. Stop timing when the you can't see the cross on the paper.
6. Wash out the flask thoroughly.
7. Repeat experiment 20mL of Sodium Thiosulfate and 30mL of Water.
8. Repeat experiment 30mL of Sodium Thiosulfate and 20mL of Water.
9. Repeat experiment 40mL of Sodium Thiosulfate and 10mL of Water.
10. Repeat experiment 50mL of Sodium Thiosulfate and no Water.

Results 

10ml of thiosulfate and 40ml of water took 3:22 seconds to react
20ml of thiosulfate and 30ml of water took 1:58 seconds to react
30ml of thiosulfate and 20ml of water took 0:57 seconds to react
40ml of thiosulfate and 10ml of water took 0:52 seconds to react

Conclusion: In conclusion the more thiosulfate you add and less water it is quicker to react and the more water and less thiosulfate you add it takes longer to react.


Experiment 3: Observing the effect of surface area on reaction rate

Aim: To make the simple observations during a reaction between calcium carbonate (CaCO3) chips powder with hydrochloric acid (HCL).

Equipment: 

• Boiling tube 
• Calcium Carbonate chips 
• Calcium Carbonate powder
• Hydrochloric Acid
• Measuring cylinder
• Spatula 

Method: 

1. Measure 2mL of hydrochloric acid and pour this int your boiling tube.
2. Holding your boiling tube over a sink or heatproof mat, add a pea-sized amount of Calcium Carbonate powder  to your boiling tube. Record your observation. 
3. Repeat the experiment but this time use a chip of calcium carbonate that is roughly the same size as the spatula of powder you used previously. Record your observation. 

Observation of Calcium Carbonate powder: When the powder reacted with the acid it fizzed up and small bubbles appeared at the top.  

Observation of Calcium Carbonate chip: When the chip hit the acid tiny bubbles came up from the bottom. 

Conclusion: 



Experiment 4  Observing the effect of a catalyst on a chemical reaction

Aim: To observe the effects of a copper catalyst on he reaction between zinc and sulfuric acid.

Equipment: 

• Three test tubes
• test tube rack 
• 10ml measuring cylinder 
• dropping pipette 
• granulated zinc
• copper turnings or powder 
• dilute sulfuric acid 

Method 

1. Add roughly the same mass of zinc in test tubes 1 and 3 
2. Add roughly the same mass of copper to test tube 2 and 3 
3. Add 5 ml of the acid to test tube 1 note the rate and production of gas bubbles
4. Add 5 ml of acid to the test tube 2 note the rate and production of gas bubbles 
5. Add 5 ml of the acid to test tube 3 not the rate of production of gas bubbles 

Test tube 1: When both products reacted it bubbled and went cloudy. 

Test tube 2: When both products reacted s few bubbles a pared and the powder went to the top and then the powder turned clear. 

Test tube 3: The products bubbled a lot and it separated. 

Catalyst: It speeds up a chemical reaction

Purpose of test tube 2: It was to show what would happen with only copper and the acid, it didn't react.