Thursday

August 28, 2014

August 28, 2014

Posted by **Cliff** on Friday, December 10, 2010 at 5:37pm.

I have posted a titration question that I'm trying to solve. The correct answer to the problem is 0.128 M, however,I have arrived at the answer: 0.000128 M. Here's the question:

If 38.30 mL of 0.250 M NaOH is used to titrate 25.0 mL of phosphoric acid,what is the molarity of the acid? The balanced equation is

H3PO4(aq)+3 NaOH(aq)--- Na3PO4(aq)+3H2O (l).

Here's how I've tried to solve for the answer:

38.3 mL solution * (0.250 mol NaOH/1000 mL)(1 mol H3PO4/3 mol NaOH)= 3.19 moles H3PO4

(3.19 mol H3PO4/25.0 mL solution)(1L\1000 mL)= 1.276*10^-4

=0.000128 M

I appreciate your help.

- Chemistry -
**DrBob222**, Friday, December 10, 2010 at 5:43pm0.0128 M is correct.

Thanks for showing your work.

Your error is in the first line. Instead of 3.19 moles, you never divided by the 1000 mL in the second term, and it should be 0.00319 moles. Then 0.00319 moles/0.025L = 0.12767 = 0.128 M.

**Related Questions**

Algebra I - Question:The number of students on the football team is two more ...

READ THIS! - Please answer my question that I posted at 6:10 quickly because I ...

Algebra - The answer in the book however says -(5x^2-17x-9)/(x-3)(x+2) so I don'...

calculus - I have posted this question earlier and had the answer given to me ...

Math - I factored 3.6x^6+2x^6-2.8x^2+3.2x as; 3.6x^7+2x^6-2.8x^2+3.2x However my...

drbob222,math - I've written back for the one i'm having trouble with of the ...

Math - I don't have any specific problems I need help with, but I'm a bit ...

Algebra - 45 ÷ 6t x 11x I have already posted this question and received an ...

Math - I posted these 2 questions a couple of days ago and although the help I ...

solving Equations - Solve x square pluse 5x subtracting by 6 equals zero? X^2 + ...