Multiple choice Why is the flame of an LPG stove blue in colour? It is due to the incomplete combustion of LPG. It is due to the presence of carbon particles. It is due to the presence of dust particles. It is due to the complete combustion of LPG. Reveal answer Fill a bubble to check yourself D Correct answer Explanation The flame of an LPG stove is blue in colour due to the complete combustion of LPG. When the LPG burns completely, the flame turns blue. Blue flame indicates dearest burning rate for a gas.