How many moles of ions are produced by the dissociation of 0.5 mol of na2co3?

The number of moles of ions that   are produced  by  the dissociation  of  o.5 mol  of Na2CO3  is   1.5  moles

    Explanation
 write the  equation  for dissociation  of  Na2CO3
that is Na2Co3 →  2Na^+(aq)  +  CO3^2- (aq)

by  use of mole ratio  of Na2CO3 to Na^+ and to  CO3^2-   which is 1:2:1  the  moles of  Na^+ =  0.5  x2 =  1mole
the  moles of CO3^2-  =  0.5  x1  = 0.5 moles

total  moles = moles  of CO^2-     +   moles  of  Na^+

that   is  1 mole + 0.5 mole =  1..5  moles