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The empirical formula of a hydrocarbon is CH₂ - OCR Gateway - GCSE Chemistry - Question 11 - 2021 - Paper 3
Question 11
The empirical formula of a hydrocarbon is CH₂. The relative formula mass of the hydrocarbon is 126.0. What is the molecular formula of the hydrocarbon? A C₇H₁₄ B ... show full transcript
Worked Solution & Example Answer:The empirical formula of a hydrocarbon is CH₂ - OCR Gateway - GCSE Chemistry - Question 11 - 2021 - Paper 3
Step 1
Step 2
Determine the ratio of the molar mass of the hydrocarbon to the empirical formula mass
Answer
Next, we will find the ratio of the relative formula mass of the hydrocarbon (126.0 g/mol) to the empirical formula mass (14.026 g/mol):
ext{Ratio} = rac{126.0}{14.026} \\ ext{Ratio} ext{ (rounded)} = 9Step 3
Calculate the molecular formula
Answer
To find the molecular formula, we will multiply the subscripts in the empirical formula (CH₂) by the ratio calculated:
egin{itemize}
ext{C: } 1 imes 9 = 9
ext{H: } 2 imes 9 = 18
ext{Thus, the molecular formula is C₉H₁₈.}
ext{The correct answer is option C.}
ext{Answer: C}
ext{C₉H₁₈}
ext{Therefore, the molecular formula for the hydrocarbon is C₉H₁₈.}
ext{Final Answer: C}
ext{C₉H₁₈}