Question

Three wide-mouthed calibrated bottles A, B and C are taken as shown in the figure above. In each of the three arrangements, a big candle is fixed in a trough and a solution of sodium hydroxide is poured into the solution into the trough. The graduated bottles are inverted over the candles. In each of A, B and C the level of the solution touches the zero mark. The bottles are taken out. In A, the candle is lit up and immediately the bottle is replaced. In B, the candle is lit up similarly but covered with the bottle filled with oxygen only. In C, the candle is lit up but it is covered with the bottle filled with nitrogen only.
a) Why was sodium hydroxide poured in the trough?
b) Explain the difference in observation in A, B and C.

Answer 1

Answer:

please show the figure first.