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Butene reacts with oxygen as shown - Scottish Highers Chemistry - Question 19 - 2022
Question 19
Butene reacts with oxygen as shown. C4H8(g) + 6O2(g) → 4CO2(g) + 4H2O(g) 100 cm³ of butene was reacted with excess oxygen. Compared with the total volume of gases... show full transcript
Worked Solution & Example Answer:Butene reacts with oxygen as shown - Scottish Highers Chemistry - Question 19 - 2022
Step 1
Calculate the Initial Volume of Gases
Answer
Before the reaction, the volume of gases consists of 100 cm³ of butene and the excess oxygen. However, since the amount of oxygen is in excess and does not limit the reaction, we will only focus on the butene's volume initially. Thus, the total initial volume is 100 cm³.
Step 2
Determine the Volume of Gases After Reaction
Answer
In the balanced equation:
C4H8(g) + 6O2(g) → 4CO2(g) + 4H2O(g)
4 moles of carbon dioxide and 4 moles of water vapor are produced for every 1 mole of butene reacting. The volumes of gases produced can be determined by the principles of stoichiometry, as gases at the same conditions occupy volumes proportional to their moles. Each mole of gas occupies the same volume, so:
Total moles of gases produced = 4 (from CO2) + 4 (from H2O) = 8 moles for every 1 mole of C4H8 reacted.
Therefore, the volume of gases after the reaction = (100 cm³ of butene) × (8/1) = 800 cm³.
Step 3
Compare the Total Volumes Before and After Reaction
Answer
Now comparing the total volume of gases before (100 cm³) and after (800 cm³) the reaction:
Total Volume After Reaction = 800 cm³ Total Volume Before Reaction = 100 cm³
Difference = 800 cm³ - 100 cm³ = 700 cm³.
Thus, we would have 700 cm³ more volume.
Step 4