Wednesday

July 30, 2014

July 30, 2014

Posted by **Anya** on Thursday, December 13, 2012 at 2:35am.

i keep getting 13.06 for this answer, but the answer is 13.37 :S

what i do is i take the negative log of the concentration which is 0.9355 which is pOH.

i know that pH = 14 - pOH

so i get pH = 13.06

where am i going wrong ? :S

thanks for help in advance!

- Chemistry -
**Anonymous**, Thursday, December 13, 2012 at 2:45amhaha I'm guessing your studying off the old chemistry multiple choice exam for tommorow's chemistry exam at ryerson?

- Chemistry -
**bobpursley**, Thursday, December 13, 2012 at 2:52amYou assumed barium hydroxide is totally dissociated. The solubility product constant is 5E-3.

- Chemistry -
**Anonymous**, Thursday, December 13, 2012 at 3:15amAnya, do you know how to do number 4 on the final chemistry exam. Please tell me.

- Chemistry -
**Anya**, Thursday, December 13, 2012 at 3:34ami figured it out, i have to multiple the concentration by 2 because of the 2 hydroxides right?

and yes i do know # 4

you want to convert 0.0354 mg/mL at 1 atm to mol/L at 0.00036 atm.

so :

(0.0354 mg/mL) x ( 0.00036)

= 1.2744 x 10^-5 mg*CO / mL

then you just want to convert units)

1.27 *10^-5 mg*CO/mL is 1.27 * 10 ^-5 g/L

multiply that by 1 mole CO/ 28 g

yyou get 4.5 * 10 ^ -7

- Chemistry -
**Anonymous**, Thursday, December 13, 2012 at 4:04amYeah I see what you did. I did the same thing in a slightly different way and got 4.5X10^-5. I see my mistake now

you have:

P1/C1=P2/C2

-----------

P1=1 C1=0.0354

P2=0.00036 C2?

-----------

1/0.0354=0.00036/C2

then you cross multiplied and then converted the value 1.27X10^-5 from grams to mols.

================================

Do you know how to do 6 can you tell me?

**Related Questions**

8th Grade Algebra- Answer Check - Solve each system of equations, give the ...

PLEASE HELP ME! PLEASE! - 1 )3x + 8y = 1 7x + 4y = 17 Answer: (3,1) 2) -3x + 5y...

Chemistry - Calculate the concentration (% W/V) of NaCl solution that was made ...

Math - One angle of an isosceles triangle is 28°. What are the other 2 angles? (...

Math - how do you solve this I keep trying and I keep getting the wrong answer. ...

chemistry - I keep thinking that 3 is the van't hoff factor for ammonium ...

Math - (7.66 • 10^2)(6.29 • 10^-4) answer then convert to scientific notation. ...

precalculus - find the trigonometric form of the following number: -7 + 4i I ...

chemistry - I keep getting wrong answers for this question. Determine the pH of ...

chemistry-confirm please - Only a chemist can be trusted with the combination to...