Ka = 1*10^-5
pKa = - log (Ka)
= - log(1*10^-5)
= 5
use:
pH = pKa + log {[conjugate base]/[acid]}
= 5+ log {1/2}
= 4.699
Answer: 4.70
19. A buffer contains a weak acid, HA, that is twice the concentration of its conjugate...
u lal g uid. 19. A buffer contains a weak acid, HA, that is twice the concentration of its conjugate base, A . If the value of K, for HA is 1.0 x 10-5, what is the pH of the buffer? ale polution2
Which concentration of a weak acid (HA) and its conjugate base (A-) will make a buffer solution whose pH value is equal to its pKa? (HA) = 0.05 M, (A-) = 0.07 M HA = 0.05 M, (A-) = 0.05 M more than one answer is correct HA = 0.05 M, (A-) = 0.01 M
A buffer is made having a weak acid concentration of 0.50 M and a conjugate base concentration of 0.67 M. If the weak acid has a Ka of 4.5 x 10-6, what is the pH of the buffer? Answer with 3 sig figs.
You wish to make a buffer solution at a pH 9.56 with the weak acid HCN (Ka = 6.9 x 10-10 ) and its salt, NaCN..What ratio of the concentration of conjugate base to the acid: ([A- ]:[HA]) is required to attain the desired pH? a. [A- ] is 2.5 × that of [HA] b. [A- ] is 5 × that of [HA] c. [A- ] is 1 × that of [HA] d. [A- ] is ½ × that of...
Consider a buffer composed of the weak acid HA and its conjugate base A?. Part A Which pair of concentrations results in the most effective buffer? Which pair of concentrations results in the most effective buffer? 0.90 M HA; 0.10 M A? 0.50 M HA; 0.50 M A? 0.10 M HA; 0.10 M A? 0.10 M HA; 0.90 M A?
Design a buffer that has a pH of 9.89 using one of the weak acid/conjugate base systems shown below pК, к, Weak Acid Conjugate Base C202 НС-04 4.19 6.4x 10-5 НРО 2- Н.РОД 7.21 6.2 x 10-8 со,2- НСОЗ 4.8 x 10-11 10.32 How many grams of the potassium salt of the weak acid must be combined with how many grams of the potassium salt of its conjugate base, to produce 1.00 L of a buffer that is 1.00 M...
What is the pH of a buffer solution that is composed of a weak acid, HA (Ka=2.58×10–5), and the conjugate base, A–, after 1.83 mL of 0.094 M HCl solution is added. The initial concentrations of the 133 mL buffer solution are [HA]=0.38 M and [A–]=0.67 M. Enter your value to two (2) decimal places.
Question 1 (2 points) The relationship between a weak acid and its conjugate base at the 1/2 neutralization point is: the weak acid's concentration is greater than the conjugate base concentration. the weak acid's concentration is less than the conjugate base's concentration the weak acid's concentration is 1/2 the concentration of the conjugate base's concentration the weak acid and conjugate base have the same concentration. Question 2 (3 points) ✓ Saved The pka of acid is 4.8. Determine the acid's...
A buffer system contains 0.225M HA (a weak acid) and 0.225M NaA (salt of the weak acid). What is the pH of the buffer? (Ka for HA = 7.2 x 10-4) a. 7.2 x 10-4 b. 4.86 c. 3.14 d. -3.14 e. not enough information
What is the pH of a buffer solution that is composed of a weak acid, HA (Ka=2.45×10–8), and the conjugate base, A–, after 2.71 mL of 0.135 M HCl solution is added. The initial concentrations of the 142 mL buffer solution are [HA]=0.7 M and [A–]=0.37 M. Enter your value to two (2) decimal places.