Question 88Steam Plants - 1st Asst/Chief

The correct answer is D) Potassium hydroxide. Potassium hydroxide (KOH) is used in the Orsat apparatus to absorb carbon dioxide (CO2) from the gas sample being analyzed. The Orsat apparatus is a device used to determine the composition of a gas mixture, and potassium hydroxide is a common absorbent for CO2 in this type of analysis. The other options are incorrect because they are not the primary absorbent used for CO2 in the Orsat apparatus. Potassium chromate, cuprous chloride, and pyrogallic acid have different uses in gas analysis, but they are not the specific reagent used to absorb carbon dioxide in the Orsat method.