Question

Why would synthesis, decomposition, and combustion be discussed together and not the other two reactions?

a) They involve the release of energy
b) They involve the creation of new substances
c) They all require a catalyst
d) They all occur at high temperatures

Answer 1

Synthesis, decomposition, and combustion reactions are grouped together because they involve the creation of new substances and involve changes in energy. Synthesis requires energy input to form bonds, while decomposition releases energy by breaking bonds. Combustion is a rapid form of decomposition that releases energy as heat and light.

Step-by-step explanation:

Synthesis, decomposition, and combustion reactions are often discussed together because they all involve the creation of new substances and changes in energy. These reactions are fundamental to understanding chemical processes:

• Synthesis reactions involve combining two or more simple substances to form a more complex product. These reactions require energy to be absorbed in order to form the bonds between atoms.
• Decomposition reactions are the opposite of synthesis reactions; they involve breaking down a complex substance into two or more simpler products. These reactions typically release energy as bonds between atoms are broken.
• Combustion reactions are a type of rapid decomposition reaction that often involves oxygen from the air and releases a large amount of energy as heat and light.

These reactions do not necessarily require a catalyst, and while they can occur at high temperatures, this is not a defining characteristic that groups them together.