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jena
Oct7-05, 12:03 PM
Hi,

My Question:

Upon evisceration, it was discovered that the frog had died due to acid ingestion. 10mL of gastric juice was found in its stomach required 7.2mL of 0.1 M NaOh for neutralization. Calculate the pH of its gastric juice.

I'm confused, how would I approach this problem.

Thank You:smile:

amcavoy
Oct7-05, 12:38 PM
Hi,

My Question:

Upon evisceration, it was discovered that the frog had died due to acid ingestion. 10mL of gastric juice was found in its stomach required 7.2mL of 0.1 M NaOh for neutralization. Calculate the pH of its gastric juice.

I'm confused, how would I approach this problem.

Thank You:smile:
Well first you might want to find the pH of the NaOH solution. Also, what have you tried?

Alex

jena
Oct7-05, 01:01 PM
So it would be like this

poH=log[H]
poh=-log[0.1]
poH=1

and

ph+poH=14
ph+1=14
ph=13

Is this correct:confused:

thank you

amcavoy
Oct7-05, 01:13 PM
So it would be like this

poH=log[H]
poh=-log[0.1]
poH=1

and

ph+poH=14
ph+1=14
ph=13

Is this correct:confused:

thank you
That looks good for the pH of the NaOH solution. Now, you want to find the pH of the gastric acid. Do you know how to do so from here?

Alex

jena
Oct7-05, 04:05 PM
No:cry: , I still don't know what to do. Also what do I do with the mL's

Thank You:smile:

Borek
Oct7-05, 07:09 PM
No need for pOH.

Calculate from simple stoichiometry amount of HCl in the gastric juice, then its concentration - once you know concentration of HCl pH calculation should be a breeze.

Best,
Borek
--
Chemical calculator (http://www.chembuddy.com/?left=chemical_calculators)s at www.chembuddy.com (http://www.chembuddy.com)
pH calculator (http://www.chembuddy.com/?left=BATE&right=right=basic_acid_titration_equilibria)
concentration conversion (http://www.chembuddy.com/?left=CASC&right=concentration_conversion)

jena
Oct9-05, 12:02 AM
Sorry to reply so late, so I would first find the concentration like so,

M1V1=M2V2

and then use the concentration to find the pH of the acid using this equation

ph=-log(H+)

Is that the correct method?

Thank You

Borek
Oct9-05, 06:45 PM
Show what you did as your answer about using M1V1=M2V2 is ambiguous.

Best,
Borek
--
Chemical calculator (http://www.chembuddy.com/?left=chemical_calculators)s at www.chembuddy.com (http://www.chembuddy.com)
pH calculator (http://www.chembuddy.com/?left=BATE&right=right=basic_acid_titration_equilibria)
concentration conversion (http://www.chembuddy.com/?left=CASC&right=concentration_conversion)

P-man
Oct9-05, 09:15 PM
Wouldn't it help if you knew the formula of the gastric juice?

Borek
Oct10-05, 07:23 PM
P-man - gastric juice contains mostly HCl.

Best,
Borek
--
Chemical calculator (http://www.chembuddy.com/?left=chemical_calculators)s at www.chembuddy.com (http://www.chembuddy.com)
pH calculator (http://www.chembuddy.com/?left=BATE&right=right=basic_acid_titration_equilibria)
concentration conversion (http://www.chembuddy.com/?left=CASC&right=concentration_conversion)

P-man
Oct10-05, 08:23 PM
Oh, sorry. I guess that's the stuff in your stomach?