Answer:
Molarity= Moles of solute/Volume of solution(in litres)
Solute:NaOH
Moles =mass/Molar Mass
Molar mass of NaOH= 22.9+16+1=39.9g/mol
Substituting
m=80/39.9
=2.0moles
Volume has to be in litres
There's 1000ml to a litre
So 500ml equals 0.5litres
Molarity = 2/0.5
= 4M.
