Answer:
167.28×10^23
Explanation:
500 ml of water weighs 500 gm.
Molecular weight of water =18 gm
So, number of moles in 500 gm of water=500/18=27.78
Number of molecules= number of moles × Avogadro's number=27.78×6.022×10^23=167.28×10^23
So, there are 167.28×10^23 molecules in 500 ml of water