The molecular formula of butene is C₄H₈ - Edexcel - GCSE Chemistry Combined Science - Question 2 - 2018 - Paper 1
Question 2
The molecular formula of butene is C₄H₈.
Which of the following is the empirical formula of butene?
A CH
B CH₂
C C₄H₄
D (CH₂)₄
Calculate the relative formula ... show full transcript
Worked Solution & Example Answer:The molecular formula of butene is C₄H₈ - Edexcel - GCSE Chemistry Combined Science - Question 2 - 2018 - Paper 1
Step 1
a) Which of the following is the empirical formula of butene?
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Answer
To find the empirical formula, we simplify the molecular formula C₄H₈. The ratio of carbon to hydrogen is 4:8, which simplifies to 1:2. Thus, the empirical formula is CH₂. The correct answer is B.
Step 2
b) Calculate the relative formula mass of butene, C₄H₈.
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Answer
To calculate the relative formula mass, we sum the atomic masses of the component atoms in C₄H₈:
Carbon: 4 × 12 = 48
Hydrogen: 8 × 1 = 8
Adding these together gives:
48+8=56
Thus, the relative formula mass of butene is 56.
Step 3
c)(i) Balance the equation for this reaction by putting numbers in the spaces provided.
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Answer
The balanced equation for the combustion of butene in oxygen is:
C₄H₈ + 6 O₂ → 4 CO₂ + 4 H₂O
Step 4
c)(ii) Describe the test to show that a gas is carbon dioxide.
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Answer
To test if a gas is carbon dioxide, pass the gas through limewater (a dilute solution of calcium hydroxide). If carbon dioxide is present, it will react with the limewater to produce calcium carbonate, which causes the solution to turn milky. The appearance of a milky precipitate indicates the presence of carbon dioxide.
