To determine the molarity of the diluted NaOH solution, we can use the dilution equation:

M1V1 = M2V2

where:

M1 = Initial concentration (0.6 M)

V1 = Initial volume (25.0 ml)

M2 = Final concentration (what we want to find)

V2 = Final volume (25.0 ml + 475 ml = 500 ml)

Plugging in the values:

(0.6 M)(25.0 ml) = M2(500 ml)

Solving for M2:

M2 = (0.6 M)(25.0 ml) / 500 ml

M2 = 0.03 M

Therefore, the molarity of the diluted NaOH solution is 0.03 M.