What is the PH of a buffer made with 0.18M HCN and 0.097M KCN?

What is the PH of a buffer made with 0.18M HCN and 0.097M KCN? How does the PH change when 0.0025M of HCl is added to the buffer if the Ka (HCN) = (4.0*10^-10) ?

Expert Solution

1)

Ka = 4*10^-10

pKa = - log (Ka)

= - log(4*10^-10)

= 9.3979

use:

pH = pKa + log {[conjugate base]/[acid]}

= 9.3979+ log {0.097/0.18}

= 9.13

Answer: 9.13

2)

Added HCl will react with CN- to form HCN

[CN-] = 0.097 - 0.0025 = 0.0945 M

[HCN] = 0.18 + 0.0025 = 0.1825 M

use:

pH = pKa + log {[conjugate base]/[acid]}

= 9.3979+ log {0.0945/0.1825}

= 9.11

Answer: 9.11

queen_honey_blossom answered 2 years ago

What is the pH of a buffer made by combining 55.0 ml of 0.450 M HCN...

What is the pH of a buffer made by combining 55.0 ml of 0.450 M HCN and 45.0 ml of 0.250 M NaCN? (Ka of HCN = 4.4 x 10^-10) Use the Henderson Hasselbach equation, and prove why you can use it.

A buffer solution that is 0.325 M in HCN and 0.325 M in KCN has a...

A buffer solution that is 0.325 M in HCN and 0.325 M in KCN has a pH of 9.40. Addition of which of the following would increase the capacity of the buffer for added H3O+? both HCN and KCN pure water HCN KCN None of the Above One or more of these choices is the answer, please answer in that format. I have already asked this question and got the wrong answer. A buffer solution is made that is 0.388...

Part A. Calculate the pH of a buffer solution that is 0.250 M in HCN and...

Part A. Calculate the pH of a buffer solution that is 0.250 M in HCN and 0.168 M in KCN. For HCN, Ka = 4.9×10−10 (pKa = 9.31). Part B. Calculate the pH of a buffer solution that is 0.240 M in HC2H3O2 and 0.190 M in NaC2H3O2. (Ka for HC2H3O2 is 1.8×10−5.) Part C. Consider a buffer solution that is 0.50 M in NH3 and 0.20 M in NH4Cl. For ammonia, pKb=4.75. Calculate the pH of 1.0 L of...

What is the pH of a solution made by mixing 500 mL of 1.00 M HCN...

What is the pH of a solution made by mixing 500 mL of 1.00 M HCN and 1.50 L of 0.250 M NaOH, and then diluting the entire solution to a volume of 3.00 L? (Ka HCN = 4.0 x 10-10) A. 8.92 B. 6.52 C. 9.88 D. 9.27 E. 5.08 To obtain one litre of a solution of pH = 7, you should dissolve in water A. Two mol of HI + two mol of CH3NH2 B. One mol...

2.Calculate the pH of a solution made by mixing 50.00 mL of 0.100 M KCN with...

2.Calculate the pH of a solution made by mixing 50.00 mL of 0.100 M KCN with 4.33 mL of 0.425 M strong acid HCl. HCN pKa = 9.21.

2. Consider a buffer made with hydrocyanic acid (HCN) and sodium cyanide. a. What chemical reaction...

2. Consider a buffer made with hydrocyanic acid (HCN) and sodium cyanide. a. What chemical reaction would describe the acid/base reaction occurring in the buffer? b. You are instructed to dissolve 4.05 grams of hydrocyanic acid in 0.500 L of water. What is the molarity of hydrocyanic acid in solution? c. You are also instructed to dissolve 9.80 g of sodium cyanide in that same 0.500 L of water. What is the molarity of the sodium cyanide in solution? d....

You are asked to prepare 1.6 L of a HCN/NaCN buffer that has a pH of...

You are asked to prepare 1.6 L of a HCN/NaCN buffer that has a pH of 9.90 and an osmotic pressure of 1.12 atm at 298 K. What masses of HCN and NaCN should you use to prepare the buffer? (Assume complete dissociation of NaCN.) Express your answers using two significant figures separated by a comma.

Question

What is the PH of a buffer made with 0.18M HCN and 0.097M KCN?

Solutions

Expert Solution

Related Solutions