Analyze the image and extract chemical reactions and formulas.

The image shows a series of chemical reactions written on a chalkboard. Here's a breakdown:

• In the top right, there is the formula Al₂O₃ which represents aluminum oxide. An arrow points to it from the left, indicating a transformation.
• In the main part of the image, there is a sequence starting with 'Ib'. This is followed by a series of reactions:
• Na → NaOH → NaHCO₃ → Na₂CO₃ → NaCl
• Below 'Na', there is a downward arrow pointing to NaCl.

In summary, the visible chemical formulas and reactions are:

• Al₂O₃
• Na → NaOH
• NaOH → NaHCO₃
• NaHCO₃ → Na₂CO₃
• Na₂CO₃ → NaCl
• Na → NaCl