Kinetics (Effect of Temperature) JC2 – AD Chemistry Tuition

What is Kinetic Energy?

Kinetic energy is the energy an object possesses due to its motion. The term “kinetic” is derived from the Greek word “kinesis,” meaning motion. Any object that is in motion, whether it’s a moving car, a rolling ball, or even the molecules in the air, possesses kinetic energy. The amount of kinetic energy depends on the mass of the object and its velocity.

How to Calculate Kinetic Energy:

The formula to calculate kinetic energy is given by:

Kinetic Energy (KE)

=½ × mass × (velocity)²

Where:

KE is the kinetic energy,mass is the mass of the object, and velocity is the velocity (speed) of the object.

It’s important to note that the kinetic energy is directly proportional to the mass of the object and the square of its velocity. This means that an object with a greater mass or higher velocity will have more kinetic energy.

The unit of kinetic energy in the International System of Units (SI) is the joule (J). In practical terms, understanding kinetic energy is crucial in various fields, such as physics, engineering, and even sports, where the calculation of kinetic energy is essential for analyzing the motion of objects.

Chemical Kinetics

Chemical kinetics is a branch of chemistry that deals with the study of the rates of chemical reactions and the factors that influence these rates. It focuses on understanding how and at what rate chemical reactions occur, the mechanisms underlying these reactions, and the factors that affect the speed of the reactions. Chemical kinetics provides insights into the dynamics of reactions, allowing scientists to predict reaction rates under different conditions and optimize reaction conditions for practical applications.

Reaction Kinetics

Reaction kinetics is a subset of chemical kinetics that specifically concentrates on the measurement and mathematical description of reaction rates. It involves the determination of the speed at which reactants are consumed and products are formed during a chemical reaction. Reaction kinetics explores how the concentrations of reactants and products change over time and aims to establish mathematical relationships between these changes.

Practical for effects of temperature for kinetics

The aim of this experiment is to determine the dependence of the rate of reaction between glucose and acidified potassium manganate 7 on temperature. 

You will be provided with three solutions. 

1. Potassium manganate (FA1)
2. Sulfuric acid (FA2)
3. Glucose solution (FA3)
   

Steps for the experiment

Preparation 

1. Fill up your burette with manganate 7 which is the (FA1) solution. 
2. Adjust the water level in your burette so that it can be seen. 
3. Using a 50 cm³  measuring cylinder, measure around 50 cm³ of your (FA1) solution. Pour it into a beaker
4. Using the same measuring cylinder, measure 50 cm³  cube of distilled water, poured into the same beaker
5. Using the same measuring cylinder, measure around 5cm³ of KmnO₄ (FA1) solution from burette into the same beaker
6. Swirl the beaker to mix the solution 

Experiment

1. Heat up the Beaker by placing it onto a tripod and heat its content up to 75 degrees Celsius and 80 degrees Celsius.
   *Caution wear the safety goggles while heating 
2. Turn on the bunsen burner 
3. Put the thermometer to monitor the temperature 
4. While the solution is being heated, pour 25cm cube of FA1 (C₆H₁₂O₆) solution into another 50cm₃ measuring cylinder, and set it aside. 
5. When the temperature of your content of a beaker reaches around 75 to 80 degrees turn  off the Bunsen burner.
6. Using a paper towel or a cloth, carefully remove your beaker and put it down on a white tile. (It is safe to remove the safety goggles at this point)  
7. Record the temperature of your solution at this point of time
8. Prepare the stopwatch 
9. Add the 25 cm cube of glucose solution(FA3). The timer should start as soon as the solution is addded.
10. Swirl the mixture once and place it back onto the white tile. 
11. Take note of the time for the solution to turn colourless and take note of the time.
12. After this is done, empty the content of the beaker and rinse the beaker of water with distilled water, and dry it with a paper towel. 

**This experiment is repeated 4 times with the same volume and solution at different temperatures.