A student burns a candle inside a sealed container over water. After the candle goes out, the water level inside the container rises. What does this observation suggest?

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Question

A student burns a candle inside a sealed container over water. After the candle goes out, the water level inside the container rises. What does this observation suggest?

Accepted Answer

C. Oxygen was used up, reducing gas pressure inside the container — When the candle burns, it consumes the oxygen inside the container. This reduces the total amount of gas and lowers the pressure, causing the external atmospheric pressure to push water up into the container. This demonstrates that oxygen makes up about one-fifth of air.

Answer

A. Carbon dioxide was produced and dissolved in water

Answer

C. Oxygen was used up, reducing gas pressure inside the container

Answer

B. Nitrogen was consumed by the burning candle

Answer

D. The candle released water vapour that condensed

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