Question

Why is it important to stopper the flask of NaOH?

1) To prevent the evaporation of NaOH
2) To prevent contamination of the NaOH solution
3) To maintain the concentration of NaOH
4) To prevent the escape of fumes from the flask

Answer 1

Stoppering a flask of NaOH is crucial to prevent evaporation and contamination, maintain its concentration, and prevent the escape of harmful fumes.

Step-by-step explanation:

It is important to stopper the flask of sodium hydroxide (NaOH) for several reasons. One of the main reasons is to prevent the evaporation of NaOH, which ensures that the solution maintains a constant concentration. This is crucial for accurate and reproducible results in experiments. Secondly, stoppering the flask helps to prevent contamination from airborne particles or other substances, which may affect the chemical nature of the NaOH solution. Thirdly, a secure stopper maintains the concentration of NaOH by avoiding the loss of solvent, which again is important for experimental consistency. Lastly, it is important to prevent the escape of fumes to ensure a safe working environment, as NaOH can be irritating to the respiratory system and eyes.