Moderate

Formalin contains _ % alcohol:

Correct answer: B. 8

  • A. 80
  • B. 8
  • C. 37
  • D. 52

Explanation

Formalin is a solution of formaldehyde (CH2O) gas dissolved in water. It also contains a small amount of methanol (CH3OH) as a stabilizing agent. The concentration of formaldehyde in formalin is typically expressed as a percentage by volume or by weight. Common concentrations of formalin include: 37-40% formaldehyde (by weight): This is the most common concentration of formaldehyde in commercial formalin solutions. 8% methanol (by volume): Methanol is added to formalin as a stabilizing agent. So, formalin contains around 37-40% formaldehyde and 8% methanol, along with water. Therefore, option b is correct.

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About Aldehydes and Ketones

Aldehydes and ketones contain the polar carbonyl group, but aldehydes are generally more readily oxidised and more reactive than ketones. Coverage includes preparation by oxidation or reduction routes, nucleophilic addition of reagents such as hydrogen cyanide and bisulfite, and tests that distinguish aldehydes from ketones.

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