# Calculating Formula!?Watch

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Thread starter 13 years ago
#1
Hello just a past paper question im stuck on thanks

One compound of Vanadium is Vanadium Oxide.

A sample of vanadium oxide contained 10.2g of vanadium and 8.0g of oxygen.

Calculate the formula of this vanadium oxide.

V = 51, O = 16

emm what im confused is that shall i multiply 16 by 2 since oxygen exists as a molecule of O2...

Thanks

From John Wood
0
13 years ago
#2
nope, you want the number of oxygen atoms in the molecule
0
13 years ago
#3
no, oxygen is only diatomic when in it's standard state (i.e not when in compounds)

divide each mass by the complimentary Mr to get no. moles in componud
8/16=0.5 moles of O
10.2/51=0.2 moles of V

then scale up to work out ratio of the proportion of the elements in the compound
0.5/0.2=2.5 moles O
0.2/0.2=1 moles V

therefore mole ratio of V:O is 1:2.5 or 2:5
therefore compound is V2O5
0
Thread starter 13 years ago
#4
That's why joining diatomic molecule with Vanadium ......
0
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