Question

sodium carbonate(Naco3.10H2o)is an important chemical calculate its formula mass in atomic mass unit

Answer 1

The atomic masses are : 
Na= 23 u, C=12 u,O= 16 u,H2O=18 u. 
Therefore,first we have to find the molecular mass of Na2, CO3 and 10H2O separately. 
So molecular mass of Na2CO3= { (23 x 2) + 12 + (16 x 3) } u 
= (48 + 60) u 
= 108 u 
And that of 10H2O= 10 {18) } u 
= 180 u 
Adding them, we get the formula unit mass of Na2CO3.10H2O = 180 u +108 u 
= 286 u.

Answer 2

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