In Year 7 Chemistry, it's super important to know about reactants and products. These terms help us understand chemical reactions. Let’s break this down together!

What Are Reactants and Products?

Think of a chemical reaction like a recipe.

• The reactants are like the ingredients you start with.
• The products are the tasty dish you end up with after cooking.

So, reactants change during the reaction to become new substances, called products.

Common Examples of Reactants and Products

1. Burning Fuels:

   • Reactants: A fuel (like methane, which is $CH_4$) and oxygen ($O_2$).
   • Chemical Reaction: When methane burns with oxygen, it produces carbon dioxide ($CO_2$) and water ($H_2O$).
   • Products: $CO_2$ and $H_2O$.
   • Illustration: $$CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O$$

2. Rusting Iron:

   • Reactants: Iron ($Fe$), oxygen ($O_2$), and water ($H_2O$) from the air.
   • Chemical Reaction: Iron reacts with oxygen and moisture to make rust, which is iron(III) oxide ($Fe_2O_3$).
   • Products: $Fe_2O_3$.
   • Illustration: $$4Fe + 3O_2 + 6H_2O \rightarrow 4Fe(OH)3$$

   (This can change into rust, $Fe_2O_3 \cdot nH_2O$).

3. Photosynthesis:

   • Reactants: Carbon dioxide ($CO_2$) and water ($H_2O$) with sunlight.
   • Chemical Reaction: Plants use sunlight to turn carbon dioxide and water into sugar ($C_6H_{12}O_6$) and oxygen.
   • Products: $C_6H_{12}O_6$ and $O_2$.
   • Illustration: $$6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$$

4. Acid and Base Reactions:

   • Reactants: An acid (like hydrochloric acid, $HCl$) and a base (like sodium hydroxide, $NaOH$).
   • Chemical Reaction: When you mix these together, they neutralize each other to make salt (sodium chloride, $NaCl$) and water.
   • Products: $NaCl$ and $H_2O$.
   • Illustration: $$HCl + NaOH \rightarrow NaCl + H_2O$$

Conclusion

These examples show how reactants turn into products through different chemical reactions. Understanding this basic idea is important in chemistry and helps us see how it affects our daily lives! Whether we are looking at burning fuels, rusting iron, how plants make food, or mixing acids and bases, knowing about reactants and products helps us understand how things interact in the world of chemistry.