Engage• Does exothermic nature of the reaction has an effect on the overall temperature of the reaction?
ConceptRate of reaction is the speed at which a reaction happens. Ifa reaction has a low rate it means the molecules combine ata slower speed than a reaction with a high rate. The factorsthat affect the rate of reaction are surface area,temperature, catalyst and concentration of the reactants.
The relationship betweentemperature and rate of reaction.
Apparatus• DrDAQ data logger connected to a PC• Two external temperature probes (DD100)• I M Hydrochloric acid• 1 cm lengths of magnesium ribbon• Two boiling tubes• Electric water bath or large beaker filled with water at 50 degrees Celsius• 25 cm3 measuring cylinder or 25 cm3 pipette
1. 20 cm3 hydrochloric acid is measured and placed in two test tubes.2. The hydrochloric acid is heated to 50 C in a water bath.3. The temperature in both test tubes is monitored using the DrDAQ.4. 1cm of magnesium is added to 1 of the test tubes.5. The temperature changes are monitor in both test tubes.
Data Analysis When we added the magnesium to the test tube,the temperature is affected by the rate of reaction.The time taken for the reaction to occur is slowerin the test tube without the magnesium ribbon..
Questions• Did the magnesium reacting effect the temperature of the reaction?• How much did the magnesium reacting increase the temperature?• How will this affects the design of the fair test for the reaction?
• Question 1 : Magnesium gives effect to the temperature of the reaction. The time taken for the reaction to occur is faster in the test tube with the magnesium ribbon.• Question 2 : 1 cm of magnesium ribbon was used in this experiment.• Question 3 : The test is run in the same environment to prevent error that may occur as well as continue to take the data while the temperature keep on changing.
Conclusion• Data logger can be used in teaching and learning to get more accurate result.• Magnesium ribbon can increase the temperature of the solution.• Temperature can changed by the influence of reaction rate. And reaction rate also are affected by the temperature.
• The bread goes bad after been left for a few days.• The temperature is the main factor why the bread become like this.• Within the time, the bread was infected by the bacteria.• This happen more quickly in warm temperature, where as cold interrupts and even stop this process.• This is the reason why food is stored in the refrigerator. The cold temperature slows down the chemical reactions that lead to its spoiling.
Steps to follow in preventing bacteria fromgrowing with the aid of temperature.• At temperature between 5c and 63c c , bacteria on food can grow to a point where they can make we ill. So, keep the fridge at 5c or below.• Keep the fridge door closed tightly, as the temperature will rise if the door is left open.• Do not put hot food in the fridge as this can raise the fridge temperature.• Do not overpack the fridge, as this can stop cool air from circulating freely and the fridge may not keep the foods properly chilled.