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SUMMARY

The pH of a 1.50M aqueous ammonia (NH3) solution is calculated to be 11.715, not 4.54 as initially stated. The dissociation of NH3 in water produces hydroxide ions (OH-) and ammonium ions (NH4+), with a base dissociation constant (Kb) of 1.8×10-5. The calculation involves determining the concentration of hydroxide ions and subsequently using the formula pH = -log(H+) to find the pH value. Therefore, the original assertion of a pH of 4.54 is incorrect.

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the question is:

What is the pH of 1.50M of NH3?
the answer i got was a pH of 4.54..
is that correct?
 
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laker_gurl3 said:
the question is:

What is the pH of 1.50M of NH3?
the answer i got was a pH of 4.54..
is that correct?
SOLUTION HINTS:
For aqueous ammonia solution:
NH3 + H2O ↔ NH4+ + OH-
Kb = 1.8×10(-5) = [NH4+][OH-]/[NH3]
::: ⇒ 1.8×10(-5) = x2/(1.5 - x)
::: ⇒ x = [OH-] = (5.18716×10(-3))
::: ⇒ [H3O+] = 10(-14)/(5.18716×10(-3))
::: ⇒ pH = 11.715


~~
 
-log(H+)=pH
What's the pH value of 1M HCl?
I am afraid the answer is wrong as NH3 is an alkali
 

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