What is used to calibrate bomb calorimetersa.Benzoic acidb.Acetic acidc.Picric acidd.Phenol

To determine which substance is commonly used to calibrate bomb calorimeters, let’s look at the options provided:

1. Benzoic acid - This is the standard substance used for calibration in bomb calorimetry. It has a known heat of combustion which makes it suitable for determining the calorific value of fuels.

2. Acetic acid - While it is an organic acid, it is not typically used to calibrate bomb calorimeters.

3. Picric acid - This compound is not commonly used for calibration of bomb calorimeters due to safety and handling issues.

4. Phenol - Although phenol can be burned in a calorimeter, it does not serve as a standard calibration substance like benzoic acid does.

Conclusion

The correct answer to the question is a. Benzoic acid. It’s widely recognized for its consistent heat of combustion, which provides reliable calorimetry results.