Which factor may interfere with acidity titration as noted in the material?

Which factor may interfere with acidity titration as noted in the material?

• A. Increased turbidity improves accuracy
• B. Higher temperature eliminates interference
• C. Dissolved gases may be lost in storage/sampling/titration (avoid vigorous shaking)
• D. Use of anticoagulants removes interference

Answer: (C)

Dissolved gases influence acidity measurements because gases like CO2 form carbonic acid in water, contributing to the sample’s acidity. If the sample loses these dissolved gases during storage, sampling, or titration—especially with vigorous shaking—the amount of carbonic acid decreases, shifting the pH and the titration endpoint. This degassing changes the measured acidity and leads to inaccurate results. Keeping samples capped and handling them gently helps preserve the dissolved gas content and yields more reliable titration data. The other options don’t address this gas-related interference: turbidity can complicate measurements, temperature changes can alter equilibria and don’t inherently fix interference, and anticoagulants don’t remove or fix the issue of gas loss affecting acidity.

Dissolved gases influence acidity measurements because gases like CO2 form carbonic acid in water, contributing to the sample’s acidity. If the sample loses these dissolved gases during storage, sampling, or titration—especially with vigorous shaking—the amount of carbonic acid decreases, shifting the pH and the titration endpoint. This degassing changes the measured acidity and leads to inaccurate results. Keeping samples capped and handling them gently helps preserve the dissolved gas content and yields more reliable titration data. The other options don’t address this gas-related interference: turbidity can complicate measurements, temperature changes can alter equilibria and don’t inherently fix interference, and anticoagulants don’t remove or fix the issue of gas loss affecting acidity.