Answer:
16.7 mL
Explanation:
Convert 250 mL to L.
250 mL = 0.250 L
Calculate the amount of moles of NaOH in 250 mL of 0.300 M NaOH.
0.250 L × 0.300 M = 0.075 mol
Using this amount of moles, you need to find out what volume of 4.50 M will give you that many moles. You can do this by dividing the amount of moles by the molarity.
(0.075 mol)/(4.50 M) = 0.0167 L
Convert from L to mL.
0.0167 L = 16.7 mL