Verified Answer :

pyromorphite

mass of Na2CO3 = 106g/mol

1 mole of Na2CO3 ------------ 106g
x moles of Na2CO3 ------------ 2.25g
x = 0.0212 moles of Na2CO3
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

mass of NaOH = 40g/mol

1 mole of NaOH ----------------- 40g
x moles of NaOH -------------------- 0.800g 
x = 0.02 moles of NaOH
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

mass of Na2SO4  = 142g/mol

1 mole of Na2SO4 ---------------- 142g
x moles of Na2SO4 ------------------ 17.75g
x = 0.125 moles of Na2SO4