Key Topics Covered:

1. Combination Reactions

   • Definition: Two or more substances combine to form a single product.
   • Example: 2H2+O2→2H2O2H_2 + O_2 rightarrow 2H_2O2H2​+O2​→2H2​O
     • Real-world example: Formation of water from hydrogen and oxygen.

2. Decomposition Reactions

   • Definition: A single compound breaks down into two or more simpler substances.
   • Example: 2HgO→2Hg+O22HgO rightarrow 2Hg + O_22HgO→2Hg+O2​
     • Real-world example: Decomposition of organic matter or water splitting into hydrogen and oxygen.

3. Displacement Reactions

   • Definition: One element replaces another in a compound.
   • Example: Zn+CuSO4→ZnSO4+CuZn + CuSO_4 rightarrow ZnSO_4 + CuZn+CuSO4​→ZnSO4​+Cu
     • Real-world example: The reaction of metals with salts, such as zinc displacing copper.

4. Double Displacement Reactions

   • Definition: Two compounds exchange ions to form new products.
   • Example: NaCl+AgNO3→NaNO3+AgClNaCl + AgNO_3 rightarrow NaNO_3 + AgClNaCl+AgNO3​→NaNO3​+AgCl
     • Real-world example: Formation of precipitates when solutions of silver nitrate and sodium chloride are mixed.