Question

How many mL of a 2.5 M NaOH stock solution would provide 20 g of NaOH

a.) 500 mL
b.) 200 mL
c.) 100 mL
d.) 300 mL

Answer 1

To provide 20 g of NaOH, 200 mL of a 2.5 M NaOH stock solution would be needed.

Step-by-step explanation:

To determine the volume of a 2.5 M NaOH stock solution needed to provide 20 g of NaOH, we can use the formula:

moles = mass / molar mass

First, calculate the moles of NaOH:

moles = 20 g / 40.00 g/mol = 0.5 moles

Now, use the formula:

molarity = moles / volume

0.5 moles = 2.5 M x volume

volume = 0.5 moles / 2.5 M = 0.2 L = 200 mL

Therefore, the correct answer is option (b) 200 mL.