Char value of Kerosene is the amount of charred oil deposition on the wick obtained after burning it in a standard wick lamp at a standard rate for 24 hours. Char value of a good quality kerosene should be less than __________ mg/kg of kerosene.

ANS:D - 500

The char value of a good quality kerosene should be less than 20 mg/kg of kerosene. Here’s why:

1. Definition: The char value, also known as the carbon residue, is the amount of carbonaceous material left as residue after burning a specified quantity of kerosene under controlled conditions. This residue forms as a result of incomplete combustion and indicates the potential for soot formation and deposition during burning.
2. Quality Indicator: For kerosene used in lamps or burners, a lower char value is desirable because it indicates cleaner combustion and less soot deposition. Higher char values can lead to increased maintenance requirements for wicks and combustion chambers, as well as potential environmental and health impacts due to particulate emissions.
3. Standard Criteria: Different standards may specify varying acceptable limits for char values in kerosene. However, a common benchmark for good quality kerosene is typically less than 20 mg/kg. This ensures efficient combustion and minimizes soot formation, which is particularly important for indoor use where clean burning is crucial.