What substance is used to remove chlorine from a bacteria sampling bottle?

The substance used to remove chlorine from a bacteria sampling bottle is sodium thiosulfate. This compound is effective for dechlorination because it reacts chemically with chlorine, neutralizing it and creating non-harmful products. Chlorine is commonly used as a disinfectant in water, but its presence in water samples can interfere with the growth of bacteria, which is crucial for accurate microbial testing.

When preparing a sample for bacterial analysis, it is essential to eliminate any residual chlorine that could inhibit the growth of bacteria. Sodium thiosulfate acts as a reducing agent, specifically targeting chlorine and thus allowing for a more accurate representation of microbial content in the water being tested.

The other substances listed do not have the same specific dechlorination properties. For instance, sodium bicarbonate and calcium carbonate are primarily used for pH adjustment and do not effectively neutralize chlorine. Potassium permanganate, on the other hand, is an oxidizing agent that would introduce more chlorine-related complications rather than remove it. Thus, sodium thiosulfate is the preferred choice for this purpose.