While sodium hydrogen carbonate can react with acids to produce carbon dioxide gas, it doesn't change color itself. Therefore, it cannot be used to visually indicate changes in pH.
If you're looking for an indicator, you'll need to consider other substances like:
* Litmus paper: Turns red in acidic solutions and blue in basic solutions.
* Phenolphthalein: Colorless in acidic solutions and pink in basic solutions.
* Methyl orange: Red in acidic solutions and yellow in basic solutions.
* Bromothymol blue: Yellow in acidic solutions, green in neutral solutions, and blue in basic solutions.
Key takeaway: Sodium hydrogen carbonate (baking soda) is not an indicator.
