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Topic: Calculation of pH  (Read 6711 times)

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Offline Lara1

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Calculation of pH
« on: June 05, 2008, 01:08:36 PM »
Hello,
this is my first post. I am taking Biology course. My question about pH calculation:
HCl is a strong acid that dissociates completely in water: HCl -- H (+) +HC (-) What is pH of 0.01 M HCl?

The answer is: H =0.01M =10 to power of -2 M, so pH =2How did they came up with 10 to the power of -2M? Did they just rounded 0.01 to 2?

Thank you in advance for the answer!!
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Offline tamim83

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Re: Calculation of pH
« Reply #1 on: June 05, 2008, 01:45:58 PM »
pH=-log[H+]
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Offline Borek

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Re: Calculation of pH
« Reply #2 on: June 05, 2008, 04:34:36 PM »
0.0001 = 10-4
0.001 = 10-3
0.01 = 10-2
0.1 = 10-1
1 = 100
10 = 101
100 = 102
1000 = 103
10000 = 104

a = 10log(a)

You really should not sleep on math lessons ;)
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Offline Lara1

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Re: Calculation of pH
« Reply #3 on: June 05, 2008, 07:34:45 PM »
Tamim83 and Borek , thanks for the answers! One second after I posted my question I understood the answer :) 
Thanks again!
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