Elemental analysis of a carbohydrate X showed the sample contained 48.7 % carbon and 8.1 % hydrogen by mass. Find the empirical formula of X.

These sorts of questions can look difficult, but if you learn the steps needed to solve them then they are all very similar.Step 1: Since we are told that X is a carbohydrate, we know that the only other constituent element must be oxygen. Step 2: Then we need to convert our percentage mass into moles. We aren't given absolute masses in this puzzle, so we can assume that the total mass is 100 g to simplify the numbers. Step 3: To convert our masses to moles we divide by the relative atomic mass of each element in turn. Step 4: Divide the moles of each element by the lowest number of moles present. In this case it is oxygen. Step 5: An empirical formula is the simplest whole number ratio of atoms of each element in a compound. In this example we can find it by doubling the numbers of moles of every element. Step 6: In step 5 you worked out the number of moles of each element in the empirical formula, but the examiner asked you to give the empirical formula so don't forget to write it clearly at the bottom of the page.

Answered by Jack B. Chemistry tutor

1231 Views

See similar Chemistry A Level tutors

Related Chemistry A Level answers

All answers ▸

What is Mass Spectrometry?


"Sulfur Dioxide can be represented as a sulfur atom with double bonds to each of two oxygen atoms, explain the shape of this molecule and predict the bond angle".


How do i know what the major and minor products of the reaction between Hydrogen Bromide and Propene would be?


Work out the number of electrons, protons and neutrons in Silicon 29 isotope.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2024

Terms & Conditions|Privacy Policy
Cookie Preferences