Unit #5 COMPOUNDS

5.9 - Information in a Chemical Formula

Number Ratio of Atoms in Na2CO3

The chemical formula of
Na2CO3
consists of:
number of
Na atoms		 number of
C atoms		 number of
O atoms
one formula unit

two Na atoms

one C atom

three O atoms
12 formula units

2(12) = 24 Na atoms

1(12) = 12 C atoms

3(12) = 36 O atoms
one dozen formula units

two dozens (= 24)
Na atoms
one dozen (= 12)
C atoms
three dozens (= 36)
O atoms
6.022 x 1023 formula units
2(6.022 x 1023) = 12.044 x 1023
Na atoms

Click to see lots of Na atoms
1(6.022 x 1023) = 6.022 x 1023
C atoms

Click to see lots of C atoms
3(6.022 x 1023) = 18.066 x 1023
O atoms

Click to see lots of O atoms
one mole formula units
(We will be covering the mole concept in details in section 7.2.)
2 moles (= 12.044 x 1023 )
Na atoms
1 mole (= 6.022 x 1023 )
C atoms


3 moles (= 18.066 x 1023 )
O atoms




 


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