Density Of Gases (Harneel Malhi)

Title: Density of Gases

Principle(s) Investigated: Density of gases in air

Standards : MS-PS1-1; MS-PS1-2; MS-PS1-6.

Materials: Candles, lighter, baking soda, vinegar, beakers

Procedure:

Submit your Hypothesis here

Place a candle inside a beaker and light it. React sodium bicarbonate and acetic acid by adding 50mL of baking soda to a 100 mL of vinegar in a 500 mL beaker. Observe what is happening with the bubbles.

Let the Carbon dioxide collect in the beaker and then pour it into the beaker (the rim specifically) containing the lit candle (DO Not pour the liquid into the beaker only pour out the gas).

Submit your tested results here

Student prior knowledge: Density of gases; Air content of gases.

Explanation: Since Carbon Dioxide is denser than air, it will sink below air inside a beaker thus blowing out the flame of the candle.

The reaction below shows what combining vinegar plus baking soda produces:

NaHCO₃ + HC₂H₃O₂--------> Na + C₂H₃O₂ + CO₂ + H₂O

Questions & Answers:

How long does it take to extinguish the candle?

Is the density of carbon dioxide greater or less than Air? Where D=M/V.

What makes up Air?

Air is made up of Nitrogen 78%, Oxygen 21% and other gases make up 1% which include Argon gas and Carbon Dioxide. As both Nitrogen and Oxygen have lower molecular weight (grams/mole) than CO2, they are less dense and therefore sinks below Oxygen and Nitrogen.

If Carbon Dioxide is denser than air, then it should be possible to hold it in a open container such as a beaker and the carbon dioxide should sink towards the bottom of the beaker blowing out the flame.

Applications to Everyday Life: The atmosphere normally contains 0.03% carbon dioxide. If Carbon Dioxide exceeds 10% of the atmosphere gases, humans would not be able to breathe and we would not survive as a species. Thus, when dealing with Carbon Dioxide, make sure there is adequate ventilation around you.

Photographs:

Videos: http://www.videojug.com/film/how-to-put-out-a-candle-without-blowing-it