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Chem question; help needed D: (1 Viewer)

ebbygoo

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Hey there.

Got a chem test tomorrow, and one of the things we need to know is how to determine empirical formula experimentally.
Yeah. How do you do it>>?

PLEASE :D
 

Prawnchip

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Ok it's easier if there's an example lol
Say you need to find the empirical formula for magnesium oxide

Method
1. Weight empty crucible and record results
2. Set up the apparatus according to the diagram (draw one lol)
3. Add magnesium sample into crucible after sanding it to remove any impurities
4. Weigh crucible and magnesium strip
5. Heat crucible and keep watch until the magnesium strip becomes white
6. Burn the Mg directly by removing the bunsen from the bottom of the apparatus to meet the mg from the top when the lid is lifted
7. Repeat step 7 until Mg is completely burnt
9. Weight crucible and burnt magnesium strip and record the results
10. Use collected data to determine empirical formula

To find empirical formula
Find the mass of Mg and the mass of Oxygen. Then calculate the number of moles and divide by the smallest number of moles. The answer would be 1 : 1 therefore MgO
 

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