how many milliliters of concentrated NaOH(19.3 M) are needed to make 8.00 L of 0.25 M base solution?
1M solution is 1 mole/liter
figure out how many moles you have in 8L of .25M = 2 moles
Now, how much 19.3M solution do you need to contain 2 moles of solute?
2/19.3 = 103.6ml