What is the pH of an ammonia solution with [OH^-] = 3.7 × 10^-3 M?

Question

What is the pH of an ammonia solution with [latex][OH^{-}] = 3.7 imes 10^{-3}[/latex] M?

Accepted Answer

STEP 1 State the given and needed quantities.

ANALYZE THE PROBLEM	Given	Need	Connect
	[latex][OH^{-}] = 3.7 imes 10^{-3}[/latex] M	[latex][H_{3}O^{+}][/latex], PH	[latex] K_{w} = [H_{3}O^{+}] [OH^{-}][/latex], PH equation

STEP 2 Enter the[latex][H_{3}O^{+}][/latex] into the pH equation and calculate. Because [latex][OH^{-}][/latex] is given for the ammonia solution, we have to calculate [latex][H_{3}O^{+}][/latex]. Using the water dissociation expression, we divide both sides by [latex][OH^{-}][/latex] to obtain [latex][H_{3}O^{+}][/latex].

[latex] K_{w} = [H_{3}O^{+}] [OH^{-}] =1.0 imes 10^{-14}[/latex]

[latex] \frac{K_{w}}{[OH^{-}]} = \frac{\boxed{[H_{3}O^{+}]} \cancel{[OH^{-}]}}{\cancel{[OH^{-}]}} [/latex]

[latex] \boxed{[H_{3}O^{+}]} = \frac{1.0 imes 10^{-14}}{[3.7 imes 10^{-13}]} = 2.7 imes 10^{-12} M[/latex]

Now, we enter the [latex][H_{3}O^{+}] [/latex] into the pH equation.

[latex]PH = - \log [H_{3}O^{+}] = - \log [1.7 imes 10^{-3}] [/latex]

[latex] \overset{Calculator Procedure}{2.7 \boxed{EE or EXP}} \boxed{+/-} 12 \boxed{\log} \boxed{+/-} \boxed{=} or \boxed{+/-} \boxed{\log} 2.7 \boxed{EE or EXP} \boxed{+/-} 12 \boxed{=} \overset{Calculator Display}{\boxed{1156863624}}[/latex]

STEP 3 Adjust the number of SFs on the right of the decimal point.

[latex]\underset{Two SFs }{2.7 imes }10^{-12} M \underset{Two SFs to the right of the decimal point }{PH =11.57} [/latex]

Question 11.9: What is the pH of an ammonia solution with [OH^-] = 3.7 × 10...

Related Answered Questions

Does the equilibrium mixture of the following reaction contain mostly reactants or products? HF(aq) + H2O(l) ⇔ H3O^+(aq) + F^-(aq) ...

Verified Answer:

The Ka for acetic acid, HC2H3O2, is 1.8 × 10^-5 . What is the pH of a buffer prepared with 1.0 M HC2H3O2 and 1.0 M C2H3O2^-? HC2H3O2(aq) + H2O(l) ⇔ H3O^+(aq) + C2H3O2^-(aq) ...

Verified Answer:

If 16.3 mL of a 0.185 M Sr(OH)2 solution is used to titrate the HCl in a 25.0-mL (0.0250 L) sample of gastric juice, what is the molarity of the HCl solution ?2HCl(aq) + Sr(OH)2(aq) → 2H2O(l) + SrCl2(aq) ...

Verified Answer:

Write the balanced equation for the neutralization of HCl(aq) and Ba(OH)2(s). ...

Verified Answer:

Calculate [H3O^+] for a urine sample, which has a pH of 7.5. ...

Verified Answer:

Aspirin, which is acetylsalicylic acid, was the first nonsteroidal anti-inflammatory drug (NSAID) used to alleviate pain and fever. If a solution of aspirin has a [H3O^+] = 1.7 × 10^-3 M, what is the pH of the solution? ...

Verified Answer:

A vinegar solution has a [OH^-] = 5.0 × 10^-12 Mat 25 °C. What is the [H3O^+] of the vinegar solution? Is the solution acidic, basic, or neutral? ...

Verified Answer:

Consider the pH of the following body fluids: a. Place the pH values of the body fluids on the list in order of most acidic to most basic. b. Which body fluid has the highest [H3O^+]? ...

Verified Answer:

Write the acid dissociation expression for the weak acid, nitrous acid. ...

Verified Answer:

Identify the conjugate acid-base pairs in the following reaction: HBr(aq) + NH3(aq) → Br^-(aq) + NH4^+(aq) ...

Verified Answer: