Question

Calculate the formula unit masses of ZnO; Na 2 O and K 2 CO 3 .
(Atomic mass of Zn = 65u, Na=23u, K=39u, C= 12u, O=16u)

Answer 1

Answer:

Zno= 81u

Na2o=62u

k2Co3=138u

Explanation:

Formula unit mass of 

ZnO=(Atomic mass of Zn)+(Atomic mass of O)

                                             =(65+16)u =81u

Formula unit mass of

 Na2O=(2×23)+16

                                              =62u

Formula unit mass of 

K2CO3=(2×39)+12+(3×16)

                                                  =138u

Answer 2

Explanation:

Given:

Atomic mass of Zn = 65u

Atomic mass of Na = 23u

Atomic mass of K = 39u

Atomic mass of C = 12u

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