In a chemical reaction, a set of reactants is converted to a set of products with different chemical compositions. A chemical reaction involves breaking old bonds and making new ones. A reaction may release energy or require its input.
learning outcomes
You should be able to:
Demonstrate an example to show that chemical reactions obey the law of conservation of matter.
Explain how energy is involved in a chemical reaction.
Using the example of the chemical equation C6H12O6 + O2 → CO2 + H2O, insert numbers so that the numbers of atoms on both sides of the equation are balanced.
X C6H12O6 + X O2 → X CO2 + X H2O
Use an example to explain how the form of energy can change during a chemical reaction.
In the burning of propane, there is a chemical transformation. Some chemical energy is released as heat and light.
We will return to chemical reactions and how they occur in living systems in Chapter 8, 9, and 10, focusing particularly on energy transformations that fuel biological processes. First, however, we will examine the unique properties of the substance in which most biochemical reactions take place: water.