Fuels and Combustion on Chemistry related Questions and Answers

Question :   Ratio of primary air to secondary air increases with increase in the rank of coal, because the 1. calorific value of the coal increases. 2. high rank coals have higher amount of volatile matter. 3. oxygen content progressively decreases. 4. ratio of fixed carbon to volatile matter increases. Answer :   4 - ratio of fixed carbon to volatile matter increases.