Molarity #="mol solute"/"L of solution"#.
You have liters of solution, but you don't have moles of solute, #"KMnO"_4"# (potassium permanganate).
However, you can determine moles #"KMnO"_4# from its given mass and its molar mass, which is #"158.0323 g/mol"#.
To determine the moles of #"KMnO"_4"#, multiply its given mass by the inverse of its molar mass.
#4.7744color(red)cancel(color(black)("g KMnO"_4))xx(1"mol KMnO"_4)/(158.0323color(red)cancel(color(black)("g KMnO"_3)))="0.030212 g KMnO"_4"#
Now that you have moles of solute and liters of solution, you can calculate molarity using the equation above.
Molarity#=(0.030212"mol KMnO"_4)/(2.000"L solution")=("0.01511 mol KMnO"_4)/(1"L solution")#
