Atom Economy (GCSE Chemistry)
Atom Economy
Atom Economy
Atom economy is the measure of the amount of starting materials that end up as useful materials.
- Atom economy is important in industry. Industries can use atom economy to measure the amount of starting materials which are transformed into useful end products.
- We can work out the proportion of ‘desired product’. Atom economy tells you the proportion of reactants that are wasted in a reaction through manufacturing. We can also work out the amount of our ‘desired product’.
- High atom economy links to sustainability. Industries always want a high atom economy. This means that the value and sustainability of a certain product will also be high.
Calculating Atom Economy
We can calculate the atom economy with the following equation.
Ideally, we want an atom economy of 100%. As we discussed earlier, atom economy shows the percentage of the reactants which form the desired product.
There are some reactions in which all the reactants form the product, which is the ideal reaction, for example:
N2(g) + 3H2 (g) <-> 2NH2(g)
C2H4 (g) + H2O (g) <-> C2H5OH(g)
These equations are reversible, meaning that any reactants which are re-formed or unreacted can be added back into the reaction vessel to be recycled.
Practice Question: A student wanted to make copper chloride by reacting copper oxide and hydrochloric acid. Calculate the percentage atom economy for the following reaction.
CuO + 2HCl -> CuCl2 + H2O
1.Work out the desired product.
Desired product = CuCl2
2. Work out Mr.
Mr CuCl2 = 63.5 + 35.5 + 35.5 = 134.5
Mr (CuO + 2HCl) = (63.5 + 16) + 2 x (1 + 35.5) = 152.5
3. Use the atom economy formula.
Atom economy = Mr of desired product/ Sum of Mr of all reactants x 100
Atom economy = 134.5/152.5 x 100 = 88.20%
Atom economy of reaction = 88.20%.
Atom economy is a measure of the efficiency of a chemical reaction. It is calculated by dividing the total number of atoms in the desired product by the total number of atoms in all the reactants. The higher the atom economy, the more efficient the reaction is considered to be.
Atom economy is important in chemistry because it provides a way to compare different reactions and determine which one is the most efficient. By choosing reactions with high atom economy, chemists can reduce the amount of waste produced, conserve resources, and minimize environmental impact.
Atom economy is calculated by dividing the total number of atoms in the desired product by the total number of atoms in all the reactants. For example, if a reaction produces 100 atoms of a desired product and 200 atoms of reactants, the atom economy would be 50%.
The benefits of having a high atom economy in a chemical reaction include reducing the amount of waste produced, conserving resources, and minimizing environmental impact. High atom economy also means that less energy is needed to carry out the reaction, which can make it more cost-effective.
Atom economy can be improved in a chemical reaction by choosing reactants that contain the desired atoms, using the minimum amount of reactants needed, and minimizing the production of unwanted side products. Chemists can also optimize the reaction conditions, such as temperature and pressure, to maximize the yield of the desired product.
Atom economy is related to sustainability in chemistry because it provides a way to measure the efficiency of a reaction and determine its impact on the environment. High atom economy means that less waste is produced, fewer resources are used, and the reaction has a lower environmental impact. By optimizing atom economy, chemists can contribute to a more sustainable future.
Yes, atom economy can be used to compare different chemical processes and determine which one is the most efficient. For example, it can be used to compare the production of a chemical from different sources or using different methods to determine which method has the highest atom economy and is therefore the most sustainable.
Examples of reactions with high atom economy include reactions that produce the desired product in a single step, with minimal waste and side products. For example, the production of ethanol from sugar using yeast is a reaction with high atom economy, as the majority of the reactants are converted into the desired product with minimal waste.
Examples of reactions with low atom economy include reactions that produce a large amount of waste and side products, and those that use multiple steps to produce the desired product. For example, the production of some plastics from petroleum has a low atom economy, as a significant amount of the reactants are lost as waste during the process.
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