Mass lost in chemical reactions?

In summary, in chemical reactions, energy is released and mass is lost according to Einstein's formula. This is also true for nuclear energy, although the amounts lost are very small. It was once believed that mass was conserved. For example, when a kilogram of coal is burned, it releases about 40 million joules of energy. To match the amount of mass lost, it would take a very large number of carbon atoms, specifically 2.0 x 10^-26 kg of mass. The formula 1H + Energy -> n + e+ + v is not relevant to this problem.
  • #1
jlp
1
0

Homework Statement



In chemical reactions, when energy is released, mass is lost according to Einstein’s formula just as it is for nuclear energy (though the amounts lost are so small that for centuries scientists thought that mass was conserved). When a kilogram of coal is burned, it releases about 40 million joules of energy.

a. What amount of mass is lost?
b. How many carbon atoms would it take to match the amount of mass that is lost?

Homework Equations



mass = 2.0 × 10- 26 kg
1H + Energy n + e+ + v ----> is this a formula that needs to be used?


The Attempt at a Solution



I am so lost...:( can anyone help!?
 
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  • #2
jlp said:


Homework Equations



mass = 2.0 × 10- 26 kg
1H + Energy n + e+ + v ----> is this a formula that needs to be used?



How is energy and mass related? You certainly remember Einstein's famous equation.

ehild
 

Related to Mass lost in chemical reactions?

1. What is mass lost in chemical reactions?

Mass lost in chemical reactions refers to the difference in mass before and after a chemical reaction has occurred. This is due to the rearrangement of atoms and the formation of new molecules.

2. Why is mass lost in chemical reactions?

The law of conservation of mass states that mass cannot be created or destroyed in a chemical reaction. However, during a chemical reaction, the mass can appear to decrease because some of the reactants combine to form new products with a different chemical composition.

3. How is mass lost calculated in chemical reactions?

Mass lost is calculated by subtracting the initial mass of the reactants from the final mass of the products. This difference in mass represents the amount of mass that has been lost during the chemical reaction.

4. Does the amount of mass lost vary in different chemical reactions?

Yes, the amount of mass lost can vary depending on the type of chemical reaction and the substances involved. Some reactions may have a small mass lost due to the formation of new bonds, while others may have a larger mass lost due to the release of gas or other byproducts.

5. How does mass lost in chemical reactions affect the overall reaction?

The mass lost in a chemical reaction is an important factor in determining the efficiency of the reaction. It can also be used to calculate the yield of a reaction and to determine the purity of the products. Additionally, the mass lost can provide valuable information about the chemical properties of the substances involved in the reaction.

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