AP Chemistry problem on Additional Aspects of Aqueous Equilibria

The pH of a solution prepared by mixing 45.0 mL of 0.183 M KOH and 65.0 mL of 0.145 M HCl is _____

A) 1.314
B) 2.923
C) 0.744
D) 1.966
E) 7.148

Please help!! And explain! I have NO idea how to start...

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Obsession is a drop of water in the desert- crave it, savor it, remember it. ~Unknown

@ crimsonsnow000117
I'm not sure if the answer is right but it should go like this:

mol of KOH = 45/1000 x 0.183 = 0.008235mol
mol of HCl = 65/1000 x 0.145 = 0.009425mol

SInce KOH is an alkali and HCl is and acid, neutralisaton occurs and since there is a HCl is greater in amount than KOH, option E is eliminated.

KOH + HCl = KCl + H2O + excess HCl
amount of excess HCl = 0.009425 - 0.008235 = 0.00119mol

Since HCl is a strong acid, pH = -log[H+]
[H+] = 0.00119/(0.045+0.065) = 0.010818mol (5sf)
pH= -log(0.010818) = 1.966 (4sf)
thus ans is D.

Please correct me if Im wrong!

Googled.

(: ,
Pika.

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@marshy03
It is D! Thank you And thank you very much for the explanation. It was really helpful~

@Pikapu
Thanks

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Obsession is a drop of water in the desert- crave it, savor it, remember it. ~Unknown

know any good way too combine these sentences?

East of Eden by John Steinbeck, is a novel that is filled with biblical allusions and is packed full of almost every theme imaginable. Themes of wickedness, goodness, love, rejection, guilt, and motherhood.

An easy way that I can think of it just add "such as" after every theme imaginable.
ex: ...and is packed full of almost every theme imaginable, such as wickedness, goodness, love, etc.

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Nulla in mundo pax sincera
"Always go too far, because that's where you'll find the truth." - Albert Camus

Ohhh that was perfect! Thank you

East of Eden, by John Steinbeck, is a novel filled with biblical allusions and almost every theme imaginable: wickedness, ethicality, love, rejection, guilt, and maternalism.

Just to let you know, the last "sentence" is a sentence fragment; therefore, it couldn't stand alone anyway.

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"Officially, this machine doesn't exist, you didn't get it from me,
and I don't know you. Make sure it doesn't leave the building."

I swear to god I hate math questions like this, I have NEVER understood them. Help, please! D:

A restaurant bill came to $60. If 15% of this amount was left as a tip, how much was the tip?

15% of $60 is 60 x 0.15 = 9.




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thank you so much!

You're welcome.

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Can anyone do some thermal physics?

A spherical balloon is filled with helium atoms (Note: 1 atm = 101.3 kPa).
(i) What is the total translational KE of the atoms if the balloon has a diameter 41.0 cm at 38.0 °C and the pressure inside the balloon is 121.6 kPa?

Answer is 6580.0 J respectively but I dunno what to do.


Last edited by qwertyqwerty11294 at 10:31 pm, Sep 15 2012

Ek=(3/2)PV
..........

This years salary, $50,220, is an 8% increase over last year's salary. What was last year's salary?