Question

A glass of water contains 1.2 x 1024 molecules of water. An additional 4.0 moles of water are poured into the glass. How many moles of water are in the
glass?

Answer 1

there are 6.0 x 1E23 molecules in a mole

2.0 moles + 4.0 moles

Answer 2

1.2E24 / 6.0E23 = 2.0 moles

4.0 moles are added