Understanding the Behavior of Litmus in NaCl and NaOH Solutions
Litmus is a natural pH indicator used to determine the acidity or alkalinity of a solution. It turns red in acidic solutions and blue in alkaline solutions.
1. NaCl Solution and Litmus
- Nature of NaCl: Sodium chloride (NaCl) is a neutral salt formed from the reaction of a strong acid (HCl) and a strong base (NaOH).
- Effect on Litmus: When NaCl is dissolved in water, it does not produce any H+ or OH- ions. Thus, the solution remains neutral (pH around 7).
- Litmus Reaction: Since NaCl is neutral, it does not change the color of blue litmus paper; it remains blue.
2. NaOH Solution and Litmus
- Nature of NaOH: Sodium hydroxide (NaOH) is a strong base that completely dissociates in solution to produce Na+ and OH- ions.
- Effect on Litmus: The presence of OH- ions makes the solution alkaline, with a pH typically above 7.
- Litmus Reaction: Blue litmus paper turns red only when exposed to acidic conditions. However, NaOH solution will not turn blue litmus to red; instead, it keeps it blue due to its basicity.
Conclusion
- Final Outcome: Neither NaCl nor NaOH will turn blue litmus paper red. NaCl remains neutral, while NaOH keeps the litmus blue. If the litmus paper turns red, it indicates the presence of an acidic solution, which is not the case here.
In summary, NaCl does not affect the litmus color, while NaOH maintains the blue color due to its basic nature.