Which of the following substances is used to absorb carbon dioxide gas in combustion analysis?
Answer: 50%KOH
Explanation
The substance used to absorb carbon dioxide gas in combustion analysis is 50% KOH (potassium hydroxide)
50% KOH (potassium hydroxide):
Potassium hydroxide is used to absorb CO (_2) because it reacts with CO (_2) to form potassium carbonate (K(_2 )CO (_3) and potassium bicarbonate (KHCO (_3)).
This makes it an effective absorbent for CO(_2) in combustion analysis.
[ 2KOH + CO_2 rightarrow K_2CO_3 + H_2O ]
[ KOH + CO_2 rightarrow KHCO_3 ]
