Answer:
79.994g NaOH
Explanation:
The formula for molarity is M=moles of solute/Liters of solution, M=n/L
You are given L and M, so 0.4=n/5
n (moles of solute) = 2
2 moles of NaOH, multiplied by the molar mass of NaOH (39.997) to get the mass needed: 79.994g
