A student burns ethanol in air and observes a blue flame. Which statement best explains this observation?
Complete combustion produces a blue flame due to sufficient oxygen supply.
Ethanol (C2H5OH) is a clean-burning alcohol. When the supply of oxygen is plentiful, ethanol undergoes complete combustion: C2H5OH + 3 O2 → 2 CO2 + 3 H2O + heat.
Complete combustion releases a large amount of energy and produces very little unburnt carbon. Because there is almost no soot to glow yellow, the flame appears clean and blue.
If oxygen were insufficient, incomplete combustion would produce carbon monoxide and unburnt carbon particles; these glow, giving a smoky, yellow or orange flame, not a blue one. Ethanol itself is not coloured by impurities, and it does not naturally give a red flame in air.
Hence, the blue flame is best explained by complete combustion due to a sufficient oxygen supply.
Similar Questions
Baking soda is commonly used in fire extinguishers because it releases a specific gas when heated. What is the gas released and how does it help extinguish fires?
Soap molecules arrange themselves in which form to perform cleaning action?
Which of the following is used as a preservative in pickles?
Which storage condition slows rancidity most effectively in edible oils and fats?
Clove oil is used as an olfactory indicator. If its smell persists in solution X but fades in solution Y, what can be inferred about the nature of the two solutions?
Which of the following carbon compounds is most likely to burn with a non-luminous flame?
Industrial machines made of steel often operate in moist environments. Which routine maintenance task is most effective in minimizing corrosion and ensuring machine longevity?
Which gas released from bleaching powder is primarily responsible for its bleaching and disinfecting action?
Why is baking soda preferred over sodium carbonate in fire extinguishers?
Refer to the two statements given below and choose the CORRECT option.
Statement A: Ethanoic acid reacts with bases to form a salt and water.
Statement B: This reaction is classified as an oxidation reaction.
Important Questions from Chemistry in Everyday Life
Which of the following is a greenhouse gas?
I. Methane
II. Nitrous oxide
Which of the following is NOT a Fossil Fuel?
Which one of the following is used in soda-acid fire extinguishers?
The separation of two immiscible liquids can be done based on the difference in their_______.
Orange juice contains ______ acid due to which it tastes sour.
