Molarity is expressed as the number of moles of solute per volume of the solution. We calculate as follows:
2.80 g ( 1 mol / 56.11 g ) = 0.05 mol KOH
Molarity = 0.05 mol KOH / 750 mL ( 1 L / 1000 mL )
Molarity = 0.07 M
Hope this answers the question. Have a nice day.