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Which pair of aqueous 1

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Which pair of aqueous 1.0 mol/L solutions could be chosen to prepare buffer?

 I  NH₄Cl(aq) and HCl(aq)

 II HF(aq) and NaF(aq)

III NH₄Cl(aq) and NH₃(aq)

 

a -I only

b -II and III only

c -None of the solutions will be a buffer

d -II only

 

 

Calculate the pH of the following solutions.

a) a solution that contains 4.8 x 10^-2 mol/L hydrochloric acid

 Answer must be in the correct number of significant digits for pH valules.

 

Calculate the pH of the following solutions.

b)     an aqueous solution that is 5.82 x 10^-3 mol/L sodium hydroxide

Answer must be in the correct number of significant digits for pH valules.

 

 

1- A solution has a pH of 3.89. What is the concentration of hydronium ion a.b x10 ^-c format. abc

 

 

2 -A solution has a pH of 3.89. What is the concentration of hydroxide ion 2 -

a.b x10 ^-cd format. abcd

 

 

 

3- The active ingredient in Aspirin™ is acetylsalicylic acid, HC₉H₇O₄ (K_a = 2.75 x 10^-5). To treat your headache after writing exams, you take two tablets dissolved in 250 mL of water. If each tablet contains 0.32 g acetylsalicylic acid, find the pH of the solution.

Proper pH significant digit is required for full marks.

 

4 -Hydrazine, N₂H₄, is a base in aqueous solution. A 0.20 mol/L solution of hydrazine in water has pH = 10.77. What is K_bfor hydrazine?

Express your answer in the a.b x 10^-c format.  abc

 

 

5 -The two acid ionization constants for oxalic acid, HOOCCOOH, are K_a1 = 5.6 x 10^-2 and

      K_a2 = 1.5 x 10^-4. What is the base dissociation constant, K_b, for OOCCOO^2-(aq)? Express your answer in the a.b x 10^-cd format.  abcd

 

 

6 - Sodium azide, NaN₃(s) has many uses. It is the chemical used to make automobile air bags inflate with N₂(g), and it is sometimes added to water to kill bacteria. What is the pH of a 0.010 mol/L aqueous solution of NaN₃(aq)? Only the azide ion, N₃^-(aq), affects the pH of water. For hydrazoic acid, HN₃(aq), K_a = 1.9 x 10^-5.

Proper pH significant digit is required for full marks.