Volume of air for complete combustion of alkane

[desmond iking]

Homework Statement

according to the model ans, the volime of oxygen produced is 25x 24 dm^3 ...



where does the 25 come from ??



or someone can show me other step of getting the ans ? thanks in advance!

according to the model ans, the volime of oxygen produced is 25x 24 dm^3 ...

 

[mfb]

Isn't that just the 25 from the chemical reaction above?
The 24dm³ is probably the molar volume.

 

[NascentOxygen]

The 25 comes from the balanced equation on that 3rd line. Until you have the reaction equation balanced, you can't determine the quantities of each of the reagents involved.

Oxygen is not produced. Oxygen is consumed in the reaction.