What's the relationship between empirical formula and molecular formula
Chemistry aqa a level
Empirical formula is the simplest whole number ratio of atoms of each element present in a compound.
Molecular formula is the actual number of atoms of each element present in a compound.
So, if you were given the empirical formula CH3 but were given a molar mass of 30g mol^-1 and asked to work out the molecular formula it must be C2H6 because the molar mass of CH3 is 15g mol^-1 because carbon is 12g mol^-1 and hydrogen is 1g mol^-1. 30/15 = 2 - so, you multiply the number of atoms in the compound in the empirical formula by 2 (or whatever number your division gives) to find the molecular formula.
Molecular formula is the actual number of atoms of each element present in a compound.
So, if you were given the empirical formula CH3 but were given a molar mass of 30g mol^-1 and asked to work out the molecular formula it must be C2H6 because the molar mass of CH3 is 15g mol^-1 because carbon is 12g mol^-1 and hydrogen is 1g mol^-1. 30/15 = 2 - so, you multiply the number of atoms in the compound in the empirical formula by 2 (or whatever number your division gives) to find the molecular formula.
Quick Reply
Related discussions
- Empirical Formula question
- Calculating the value of x in M. H2O
- a level chemistry
- really hard exam question please help me!!
- Amount of Substance question
- How do you do NMR questions!?
- A level chem help needed. question about molecular ions??
- Would I have lost marks for this (OCR A chem)
- A-level Chem Question
- A level chemistry question help.
- Chem Multiple choice % yield Q!
- University Examinations
- AS chemistry
- AQA A Level Chemistry Paper 3 20th June 2018 Unofficial Markscheme
- AS level chemistry help- exam soon
- Help chemistry alevel
- Chemistry
- Chem
- Dimensional Analysis
- GCSE Chemistry Past Paper Question
Latest
Last reply 1 minute ago
Amazon Project management apprenticeship 2024Last reply 2 minutes ago
My boyfriend left me because he said my breasts and butt were too smallLast reply 2 minutes ago
HSBC Degree Apprenticeship 2024Last reply 3 minutes ago
Official University College London Applicant Thread for 2024Last reply 4 minutes ago
emmanuella's study discussions #2: taking breaksLast reply 5 minutes ago
Official University of St Andrews Applicant Thread for 2024Last reply 9 minutes ago
Edexcel GCSE Geography A Paper 1 (1GA0/01) - 17th May 2024 [Exam Chat]Last reply 9 minutes ago
Customer Services Group - Operational Delivery - Administrative OfficersLast reply 10 minutes ago
Official Cambridge Postgraduate Applicants 2024 ThreadLast reply 10 minutes ago
AQA GCSE Physics Paper 1 (Higher Tier triple) 8463/1H - 22nd May 2024 [Exam Chat]Last reply 11 minutes ago
How to Write an A* Prose Essay (A-level English Lit)Last reply 12 minutes ago
Religion Politics and Society at King's College?
