Question

>c) How are the following conversions carried out? Give equations only:>1) Na2co3, A , NaNO3, B,O2>ii) Mg,A, Mg(NO3)2, B , NO2 C,HNO3,>​

Answer 1

your question is incompelete , well i've understood what must be your question

Relative number of moles of an element = % of element / atomic mass

or atomic mass = % of element / relative number of moles

Atomic mass of A = 70 / 125 = 56

and atomic mass of B = 30 / 1.88 = 16

empirical formula = $A_{2}$$B_{3}$

calculation of molecular formula

empirical formula mass = 2*56 + 3 *16 = 160

n = molecular mass / empirical formula = 160/160 = 1

Molecular formula = $A_{2}$$B_{3}$