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Question
Calculate the number of atoms of each kind in 5.3 grams of sodium carbonate.
Solution
Molecular mass of Na2CO3 = 106 g
106 g has 2 x 6.02 x 1023 x 2 atoms of Na
So, 5.3g will have = `(6.02 xx 10^23 xx 2)/106 xx 5.3`
= 6.022 x 1022 atoms
Number of carbon atoms = `(6.02 xx 10^23)/106 xx53/10`
= 3.01 x 1022 atoms
And number of oxygen atoms = `(3 xx 6.02 xx 10^23)/106 xx 53/10`
= 9.03 x 1022
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