======Neutralization of Acid and Base======


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**Alternative titles:** Hydrochloric Acid and Sodium Hydroxide Reaction
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====Summary====                   
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====Procedure====  
  - Pour a measured amount of sodium hydroxide solution into a beaker.  
  - Dip a piece of red litmus paper into the solution to confirm it is basic (it will turn blue).  
  - Using a dropper, add dilute hydrochloric acid slowly to the sodium hydroxide.  
  - After each addition, stir gently and test with fresh litmus paper.  
  - Continue adding the acid drop by drop until the litmus paper no longer changes color, indicating the solution has been neutralized.



====Links==== 
Neutralisation Reaction of Sodium Hydroxide and Hydrochloric Acid- KClass Plus: 
{{youtube>Wsq0Omek9Zw?}}\

📄 The “reaction of sodium hydroxide and hydrochloric acid” - MEL Science: [[https://melscience.com/AU-en/articles/reaction-sodium-hydroxide-hydrochloric-acid/?srsltid=AfmBOopZkbftCcMgEwMiaq0RcP99CU1YOdMrRgaXt_wcUyHIGah59iVo]]\\


====Variations====
  * Use universal indicator or a pH probe instead of litmus paper to track the exact pH changes.  
  * Try other acid-base combinations, such as acetic acid with sodium hydroxide.  
  * Demonstrate the reaction with phenolphthalein as an indicator to show the color change from pink to colorless.
  * [Don't do this!] Ensure the solution is completely neutral then taste the salt water produced.  Reasons not to do this include:
      * Lab chemicals may contain impurities or contaminants not safe for ingestion
      * Even after neutralization, small amounts of excess acid or base may remain, making the solution harmful.
      * Safer and more accurate methods (indicators, pH probes) exist to test the reaction instead of tasting.




====Safety Precautions====
  * Wear safety goggles and gloves to protect from splashes.  
  * Handle hydrochloric acid with care; it is corrosive.  
  * Avoid contact of sodium hydroxide with skin, as it can cause burns.




====Questions to Consider====
  * What is the chemical equation for the reaction? (HCl + NaOH → NaCl + H₂O)  
  * Why is the acid added drop by drop instead of all at once? (To carefully control the neutralization point and avoid adding excess acid.)  
  * How does litmus paper indicate when neutralization has occurred? (The paper stops changing color, showing the solution is neither acidic nor basic.)  
  * What would happen if too much acid were added? (The solution would become acidic, and the litmus would remain red.)