Here is a question sent in via email by an avid student reader of this chemistry blogsite.
Hope to see some suggested answers below and the reasoning/explanation to it.
PS: Remember – Do not be afraid of making mistakes now. I rather you make mistakes now then during your examinations.
Question 1:
20cm3 of a gaseous hydrocarbon was mixed with 100cm3 of oxygen and the mixture sparked so that the hydrocarbon was completely burnt. The volume of gas remaining at the end of the combustion was 70cm3. After passing over soda lime, this volume was reduced to 10cm3. All gases were measured at 25C and at the same pressure.
(a) What volume of oxygen gas remained unburnt at the end?
(b) What volume of oxygen gas was used in the combustion?
(c) What volume of carbon dioxide was produced in the combustion?
(d) Deduce the formula of hydrocarbon.