Question

calculate the formula unit masses of na2o and k2co3,given atomic masses of na=23 o=16 k=39 c=12

Answer 1

Formula unit mass of ZnO = atomic mass of Zn + atomic mass of O

=(65 + 16)u = 81u

Formula unit mass of Na2O = 2 X atomic mass of Na + atomic mass of O

=(2 X 23 +16)u = 62u

Formula unit mass of K2CO3 = 2 X atomic mass of K + atomic mass of C + 3 X atomic mass of O

=(2 X 39 +12 + 3 X 6)u = (78 + 12 + 48)u = 138u

Answer 2

ANSWER :-

The formula unit mass of

(i) ZnO = 65 u + 16 u = 81 u

(ii) Na2O = (23 u x 2) + 16 u = 46 u + 16 u = 62 u

(iii) K2C03 = (39 u x 2) + 12 u + 16 u x 3

= 78 u + 12 u + 48 u = 138 u