|Image by bdyczewski from Pixabay|
Definition of the rate of chemical reaction:
The rate of the reaction is the speed at which reaction takes place. In a simple way, The speed at which the reactant molecules converted into product molecules. If the rate of the reaction is low, the speed of conversion of reactants into products is slower. If the rate of reaction is high, the speed of conversion of reactants into products is high. It can be represented mathematically as follows.
A ⟶ Product
Rate ∝ (concentration of A)ⁿ
Rate ∝ [A]ⁿ
Rate = k [A]ⁿ
Here, k, [A], and n are represented as the rate constant, the concentration of A and the order of the reaction. The rate of any reaction is directly proportional to the concentration of reactant with respect to the order of the reaction.
|Rate of reaction graph|
What is the order of the reaction?
Order reaction (n) is the power of reactant concentration. n can be any possible number from zero, one, second, third, etc. If the order of the reaction (n) is one, the graph between the rate and concentration of the reactant follows linear functionality. If the order of the reaction (n) is higher, then above said graph follows non-linear functionality. The zero order reaction undergoes independent of reactant concentration.
What is the Zero order reaction?
The rate of reaction is independent of reactant concentration. This type of reaction is called zero order reaction. Most of the catalyst activates reaction follows under this category. The biochemical reaction inside our body or in the test tube, it follows this category.
Just imagine, if you love to east some chocolate or sweet in excess, then the body should produce more concentration of insulin. The body won’t produce excess anything. If it produces excess biochemical, then the body becomes the storehouse of disease.
Biochemical reactions occur when the molecules are converted into different biomolecules. The chemist who studies the chemical process is interested in the speed of this conversion, or “biochemical reaction,” happens.
How to find the rate of reaction for biochemicals?
There are many different ways to find the rate of a biochemical reaction. For example, hydrogen peroxide (H₂O₂) reacts to an enzyme called catalase and which produces oxygen and water. It is one of the simple biochemical reactions. It gives a huge number of bubbles from the reaction medium due to the evolution of oxygen gas.
In this post, we are not going to use the complex mathematical equation to determine the rate of the reaction. If we add a drop of dishwashing detergent in the reaction medium, it combines with oxygen gases to produce the foam. We can measure the height of the foam as the method to find the rate of reaction. This information is helpful for 9th grade science projects.
Science fair project idea for the rate of the reaction experiment for 9th grade science projects :
The following materials are required for the rate of biochemical reaction experiment for 9th grade science projects.
- Test tube ——- 3 nos
- 3% of Hydrogen peroxide (H₂O₂) ——- 500 ml
- Dishwashing detergent ——- 100 ml
- Animal liver ——- 25 gm
- Gloves ——- 12 pairs
- Safety glass ——- One
- Distilled water ——– 1 L
- 50 cm scale ——- One
- Thermometer ——- One
- Heater —— One
Animal liver contains more amount of catalase enzyme. You can use the liver of beef, goat, lamb, and chicken.
|Catalase enzyme reaction with Hydrogen peroxide|
Standard Operating Protocol for the rate of the reaction:
- Put the safety glass and gloves before starting the reaction.
- Take the three cleaned test tubes and add one-third of 3% of Hydrogen peroxide (H₂O₂).
- Add one drop of dishwashing detergent.
- Add the weighed amount of small liver cube (ex: 100 mg, 300 mg, and 600 mg).
- Bubbles start to evolve out of the test tube and increase the foam height.
- when the bubbling stops from test tubes, mark the foam level of the liquid when it is calm.
- Measure the distance between the calm level and the maximum foam level of the test tubes.
- Note down the temperature before the addition of the liver and the reaching maximum foam level (Maximum temperature).
- Measure the foam height in the 50 cm scale in the notebook.
Observation of the rate of the reaction:
This height of foam from the calm level gives the relative rate of the reaction. If the height is higher in the test tube, then the rate of the reaction is faster. If the relative height is smaller in the test tube, then the rate of the reaction is slower.
Temperature affect of catalase enzyme reaction:
The liver sample is heated to above the room temperature such as 30 ⁰C, 35 ⁰C, 40 ⁰C, 45 ⁰C, 50 ⁰C, 55 ⁰C, and 60 ⁰C. So that we get a more relative rate of the reaction data. It gives a more comprehensive review of catalase reaction with respect to temperature.
Compare catalase enzyme reaction in different food sources:
You can compare with different animal liver resources as mentioned above. In this way, we can compare the catalase reaction activity with different food sources.
How are the following aspects of a reaction affected by the addition of a catalyst?
When a catalyst is added to a reaction, the activation energy of the reaction is reduced, resulting in a faster reaction rate. It does not initiate the reaction, but it does reduce the amount of energy needed to initiate one.
What is the average rate of consumption of H+ during the same time interval?
It will be in femto second range
How to calculate rate of reaction?
The formula rate = [C]/t is used to quantify the reaction rate, where [C] is the difference in product concentration over time period t.
Observing the absence of a reactant or the presence of a substance over time will reveal the rate of reaction.