Calculate the percent composition of the element (Show All Work)

Question

Formula: Na2CO3

Answer 1

I mole of Na₂CO₃ contains   2 moles Na,  3 moles O, and one mole of C.   In grams this is

2 *23 grams of Na, 3 * 16 grams of O and 12 grams of C

 

46 + 48 + 12 = 106 grams total.

percent Na = 46/106   =  43.4%

percent O   = 48/106   =  45.3%

Percent C   =  12/106   = 11.3%

 

Total                              100.0%