1) Use the Acid-Base table to determine the pKa of the weak acid HCN.
2) What is the pH of a 0.00412 M solution of HCl?
3) What is the pH of 0.00685 M solution of NaOH?
ans 1
the weak acid HCN, Ka= 6.0x10-10,
pKa = -log Ka = 9.22.
ans 2
pH = -log [H+] = -log (0.00412)
pH=2.39
ans 3
pOH = -log [OH-] = -log (0.00685)
pOH=2.16
pH + pOH = 14
pH = 14-pOH = 14-2.16
pH = 11.8
1) Use the Acid-Base table to determine the pKa of the weak acid HCN. 2) What...
PART A. Determine the pH of a 9.553 mM weak acid solution that has a pKa of 8.83 PART B. Calculate the pH of a 319 mM weak base solution with a pKb of 9.04. PART C. Determine the pKa of a weak acid solution that has an initial concentration of 0.334 M and a pH of 4.54. Hint: You know the pH of the solution, so you can easily determine x in your ICE table PART D. Calculate the...
The pka of a weak acid is useful for identification of an unknown acid because it is a constant (as long as temperature remains the same). When a weak acid is titrated with a strong base, the pka of the weak acid equals the pH at the half-equivalence point. A 0.3210 g sample of weak monoprotic acid is delivered into laboratory glassware. It will be used for titratation against 0.1254 M NaOH. If the molar mass of the weak acid...
1 . If a buffer solution is 0.260 M in a weak acid (?a=8.3×10−5)and 0.480 M in its conjugate base, what is the pH? pH= 2. If a buffer solution is 0.200 M in a weak base (?b=5.0×10−5) and 0.530 M in its conjugate acid, what is the ph 3. Phosphoric acid is a triprotic acid (?a1=6.9×10−3, ?a2=6.2×10−8 , and ?a3=4.8×10−13 To find the pH of a buffer composed of H2PO4 - (aq) ) and HPO4 2− (aq) , which...
In a weak acid when [HA]=[A-]the pH = the pKa. What is the pH after adding 0.50 moles HCl to a solution of HA =1 mole and A- = 1 mole. The pKa of the weak acid = 4
Consider a weak base that has a pKb of 4.2. • What is the pKa of this solution? • What is the pH of a 0.2 M solution of this base? • If you were to mix 50 mL of the 0.2 M base with 50 mL of a 0.1 M solution of its conjugate acid, what would the pH of this buffer be, and what is its effective buffering range?
1. What is the pH of a solution which is 0.025 M in weak base and 0.039M in the conjugate weak acid (Ka = 7.1 × 10-6)? 2. A buffer solution is made using a weak acid, HA , that has a pKa of 5 . If the pH of the buffer is 8 , what is the ratio of [A−] to [HA] ? 3.A buffer solution is made using a weak acid, HA . If the pH of the...
In the titration of 0.04 M weak base B of 50mL with 0.100 M HCl, what is the solution pH after 3 mL HCl is added? pka of the conjugate acid of base (B) is 7.9
What volume of 1.900-M NaOH should be added to 450. mL of 1.110-M solution of HCN (pKa = 9.40) to prepare a pH = 10.25 buffer? (use acid base table)
1. Calculation of pH. A weak acid HA (pKa = 4.85) reacted with strong base NaOH The reaction is HA + NAOH H20 + NaA. There are 100 mL 0.100 M HA solution, and the concentration of Na OH is 0.100 M. 0 moles a. What is the pH when 0.00 mL of NaOH is added to the 100 mL HA solution? 2 x1 les b. What is the pH when 20.0 mL of NaOH is added to the 100...
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...