2. Phoebe was tasked to ensure that an enzyme responsible for keeping her species from extinction remains biologically active. To do so, she needs to store it in a buffer solution with a pH of 10.00. Unfortunately, only three buffer systems are available in their laboratory: Buffer System Weak Acid Component Ka Conjugate Base Salt PAH SAD DOH Benzoic acid, C6H5COOH 6.25 x 10-5 NaC6H5COO Boric acid, H3BO3 5.81 x 10-7 NaH₂BO3 Hydrogen cyanide, HCN 6.20 X 10-10 NaCN

Please solve the question step by step and way with the correct answer.

5mL of 0.150 M ammonia (NH3) is titrated with 0.100 M hydrochloric acid (HCl) The Kb for ammonia is 1.75 x 10-5  1)Write a balanced chemical equation for the reaction of ammonia and hydrochloric acid and a balanced chemical equation for the equilibrium of ammonia in water. 2) What is the pH of the ammonia solution prior to the addition of any HCl?

Which of the following aqueous solutions are good buffer systems? O 0.36 M hydrofluoric acid + 0.23 M potassium fluoride O 0.27 M hydrochloric acid + 0.22 M sodium chloride O 0.15 M potassium hydroxide + 0.24 M potassium chloride O 0.15 M hydrocyanic acid + 0.15 M sodium cyanide O 0.27 M ammonium bromide + 0.33 M ammonia

Chemistry (Part -3) =============

Determine the concentration of CH NH¸* in a buffer solution by constructing an ICE table, writing the equilibrium constant expression, and use this information to determine the concentration of CH NH+. The Kb for CH NH₂ is 3.8 × 10-10. Complete Parts 1-3 before submitting your answer. 2 1 2 3 NEXT > 2 A buffer solution contains dissolved CH NH and CH NH Cl. The initial concentration of CH NH2 is 0.50 M. The pH at equilibrium of the buffer is 4.20. Let x represent the original concentration of CH NH+ in the water. Fill in the ICE table with the appropriate value for each involved species to determine concentrations of all reactants and products. Initial (M) Change (M) Equilibrium (M) CH NH2(aq) + H₂O(I) = OH(aq) + C HẠNH, (aq) RESET 0 0.50 x 4.20 -4.20 6.3 x 10-5 -6.3 x 10-5 1.6 × 10-10 -1.6 × 10-10 3.8 × 10-10 -3.8 × 10-10 x +4.20 x-4.20 x + 6.3 x 10-5 x - 6.3 × 10-5 x + 1.6 × 10-10 x-1.6 × 10-10 x + 3.8 × 10-10 x - 3.8 × 10-10

A 29.6 mL sample of 0.271 M dimethylamine, (CH3)2NH, is titrated with 0.237 M hydrobromic acid. After adding 12.9 mL of hydrobromic acid, the pH is Use the Tables link in the References for any equilibrium constants that are required.

+ pH Changes in Buffers When a solution contains a weak acid and its conjugate base or a weak base and its conjugate acid, it will be a buffer solution. Buffers resist change in pH following the addition of acid or base. A buffer solution prepared from a weak acid (HA) and its conjugate base (A) is represented as HA (aq) → H¹ (aq) + A (aq) The buffer will follow Le Châtelier's principle. If acid is added, the reaction shifts to consume the added H+, forming more HA. When base is added, the base will react with H+, reducing its concentration. The reaction then shifts to replace H+ through the dissociation of HA into H+ and A™. In both instances. [H] tends to remain constant. The pH of a buffer is calculated by using the Henderson-Hasselbalch equation: A] pH =pK₂ +log HA ▼ Part A pH = What is the pH of a buffer prepared by adding 0.607 mol of the weak acid HA to 0.507 mol of NaA in 2.00 L of solution? The dissociation constant K₁ of HA is 5.66 x 10-7 Express the pH numerically to three…

Calculate the change in pH when 0.280 mol H+ is added to 1.00 L of each of the following buffers   If the final pH is lower than the initial, your answer should be a negative number. a 0.540 M  solution of pyridine (py) containing 0.500 M  pyH+change in pH =     If the final pH is lower than the initial, your answer should be a negative number. a 0.620 M  solution of aniline (an) containing 0.920 M  anH+change in pH =

For different enzymes, there is an optimum pH at which the enzyme is most active. For example, for enzymes of gastric juice optimum pH 1-2, for duodenal enzymes pH 7.7, for liver enzymes pH 9.5, etc. Determine which medium (a or b) is most favorable for each of the enzymes mentioned above if the following substances are added to 1.0 liter of water: a) 0.040 mol KOH and 0.030 mol HBr; b) 4.0 10-9 mol HNO3. Neglect the change in the volume of the solution. Confirm your answer with calculations.