Calculate the formula unit masses of ZnO, Na2O, K2CO3, given atomic masses of Zn = 65u, Na = 23 u, K=39u, C = 12u, and O=16u.
ScienceClass 9CBSEAnswered 27 Mar 2026
Answer
Solution:
Given:
The atomic mass of Zn = 65u
The atomic mass of Na = 23u
The atomic mass of K = 39u
The atomic mass of C = 12u
The atomic mass of O = 16u
The formula unit mass of ZnO= Atomic mass of Zn + Atomic mass of O = 65u + 16u = 81u
The formula unit mass of Na2O = 2 x Atomic mass of Na + Atomic mass of O = (2 x 23)u + 16u = 46u + 16u = 62u
The formula unit mass of K2CO3 = 2 x Atomic mass of K + Atomic mass of C + 3 x Atomic mass of O = (2 x 39)u + 12u + (3 x 16)u = 78u + 12u + 48u = 138u
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