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ally1h
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Homework Statement
How would you prepare 5.00 L if an aqueous solution having a pH = 10.70, if you had a supply of 0.250 M NaOH?
Homework Equations
I don't even know anymore...
The Attempt at a Solution
I've tried a million different ways but I never come up with the answer provided in the book, which is 10 mL.
Here are two ways I've tried:
pH = 10.7; so pOH = 14.0-10.7 = 3.3
antilog (-3.3) = 5.0x10^-4 M
m1v1 = m2v2
v2 = m1v1 / m2 = (0.250 M x 5000 mL) / (5.0x10^-4) = 2500000 mL
That's DEFINITELY not right...
Second attempt:
5000 mL has x moles NaOH
5.0x10^-4 M / 5 L = 1x10^-4 moles NaOH
1x10^-4 mol NaOH x (40.0 g/mol) = 0.004 g NaOH
density of NaOH = 2.13 g/mL; so 0.004 g / 2.13 g/mL = 0.0018 mL
And that's not right either...
I'm missing SOMETHING and I've been working on this problem forever. Please help?