Question

2. Calculate the formula unit
masses of Zno, Na2O, K2 CO3
given atomic masses of Zn = 65 u,
Na = 23 u, K= 39 u, C = 12 u.
and O = 16 u.​

Answer 1

Zno Zn=1 atm= 65u

        0=1 atm= 16u

       total mass =65+16

                            81u

Na2o Na = 2 atm =23*2=46u

          o = 1atm = 16 u

             total mass = 46 +16

                                   62 u

    K2Co3   K = 2atm = 39*2 =78u

                    C= 1 atm = 12 u

                      O = 3 atm = 16*3 =48u

                    total mass = 78+12+48

                                            138 u

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