8.52 grams K2CO3 = moles

Question

any 

Answer 1

Molar mass K2CO3 = 138.205 g/mole

8.52 g x 1 mole/138.205 g/mole = 0.0616 moles 

It looks like you've posted lots of questions that are similar.  You should be able to convert g to moles and moles to g.