Checking a chem. questions answer

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The pH of a 1.50M ammonia (NH3) solution is incorrectly calculated as 4.54. The correct calculation shows that the pH should be approximately 11.715, as ammonia is a weak base that produces hydroxide ions in solution. The dissociation of NH3 in water leads to a basic solution, confirming that the initial answer was wrong. The discussion emphasizes the importance of using the correct equilibrium constant (Kb) and formulas to determine pH accurately. Understanding the properties of ammonia as an alkali is crucial for correct pH calculations.
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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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