# What is the ionization constant of a weak acid with pKa = 8.0?

28,442 results
1. ## chemistry

Strong base is dissolved in 665 mL of 0.400 M weak acid (Ka = 3.69 × 10-5) to make a buffer with a pH of 3.94. Assume that the volume remains constant when the base is added. HA(aq) + OH-(aq) -> H2O(l) + A-(aq) Calculate the pKa value of the acid and

2. ## Chemistry help!!

Consider the titration of the weak acid HA with NaOH. At what fraction of Ve does pH = pKa - 1? At what fraction of Ve does pH = pKa + 1? Calculate the pH at these two points plus Vb = 0, 1/2Ve, Ve and 1.2Ve, if 100 mL of 0.100 M anilinium bromide (pKa =

3. ## Chemistry

Strong base is dissolved in 675 ml of 0.200 m weak acid (ka=3.25x10^-5) to make a buffer with a ph of 3.95. Assume that the volume remains constant when the base is added. HA + OH ---> H2O + A^- calculate the pka value of the acid and determine the number

4. ## Chem

Please someone Help!! Acetic acid, CH3COOH, is a weak organic acid, pKa 4.47. Determine the position of the equilibrium for the reaction of acetic acid with NaHCO3, and draw the species that predominates at equilibrium.

5. ## Chem

What simplifying assumptions do we usually make in working problems involving equilibria of salts of polyprotic acids? Why are they usually valid? Answer by selecting all true statements. Are the answers: a,b,d,and f A)If the two ionization constants are

6. ## Chemistry

Describe how to prepare 10 mL of 0.200 acetate buffer, pH 5.00, starting with pure acetic acid and solutions containg 3 M HCl and 3 M NaOH. Include both quantitate and qualitative details. I know that a strong base reacts completely witha weak acid because

7. ## chemistry

What is the percent ionization of a 1.38 mol/L weak acid if its Ka = 2.7 x 10-6? Answer to two (2) decimal places. I know what steps to use but have difficulty applying them to the quesiton Can someone please complete the question for me since there are

8. ## Analytical Chemistry 2

Consider the titration of the weak acid HA with NaOH. At what fraction of Ve does pH = pKa - 1? At what fraction of Ve does pH = pKa + 1? Calculate the pH at these two points plus Vb = 0, 1/2Ve, Ve and 1.2Ve, if 100 mL of 0.100 M anilinium bromide (pKa =

9. ## Urgent Chem Help

Question.. Nicotinic acid (niacin) is a monoprotic acid with the formula HC6H4NO2. A solution that is 0.012M in the nicotinic acid has a pH of 3.39 at 25C. what is the acid-ionization constant, Ka and pKa for this acid at 25C? Attempt.. HC6H4NO2 C6H4NO2- +

10. ## chemistry

Calculate the ionization constant, Ka, of phenol (HC6H5O), a weak acid, if a 0.25 M solution of it has a pH of 5.24.

11. ## Chemistry

The pH of a 0.010 M aqueous solution of a weak monoprotic acid, HX, is 4.5. What is the value of the acid ionization constant?

12. ## CHEM HELP

Nicotinic acid (niacin) is a monoprotic acid with the formula HC6H4NO2. A solution that is 0.012M in nicotinic acid has a pH of 3.39 at 25*C. What is the acid-ionization constant, Ka and pKa for this acid at 25*C? is the ionization equation: HC6H4NO2+

13. ## AP CHEMISTRY

Phosphoric acid is triprotic acid (three ionizable hydrogens). The values of its stepwise ionization constants are Ka1= 7.5E-5, Ka2= 6.2E-8, and Ka3= 4.2E-13 1) Write the chemical equation for the first ionization reaction of phosphoric acid with water

14. ## chemistry

2- A 0.310 M solution of a weak acid, HX, has a pH of 2.53 a. Find the [H+] and the percent ionization of nitrous acid in this solution. b. Write the equilibrium expression and calculate the value of Ka for the weak acid. c. Calculate the pH of the

15. ## Chm 2

The question asks, Consider the following weak acids and their Ka values Acetic acid Ka = 1.8x10^-5 Phosphoric acid Ka = 7.5x10^-3 Hypochlorous acid Ka = 3.5x10^-8 What weak acid-conjugate base buffer system from the acids listed is the best chouce to

16. ## chemistry

What is the percent ionization of a 1.38 mol/L weak acid if its Ka = 2.7 x 10^-6? Thanks again!

17. ## chemistry

Suppose that 0.483 g of an unknown monoprotic weak acid, HA, is dissolved in water. Titration of the solution with 0.250 M NaOH(aq) required 42.0 mL to reach the stoichiometric point. After the addition of 21.0 mL, the pH of the solution was found to be

18. ## Chemistry

the ka value of 0.001moldm-3 solution of a weak acid is 1.6*10-6 calculate the ph and the pka

19. ## CHEM HELP!

Nicotinic acid (niacin) is a monoprotic acid with the formula HC6H4NO2. A solution that is 0.012M in nicotinic acid has a pH of 3.39 at 25*C. What is the acid-ionization constant, Ka and pKa for this acid at 25*C?

20. ## chemistry

A 0.010 M solution of a weak monoprotic acid has a pH of 3.70. What is the acid-ionization constant, Ka, for this acid? a. 2.0 ´ 10-4 b. 2.0 ´ 10-5 c. 4.0 ´ 10-6 d. 4.0 ´ 10-7 e. 4.0 ´ 10-8

21. ## Chemistry 104

A 0.30M solution of a weak monoprotic acid is 0.41% ionized. what is the acid-ionization constant, Ka for this acid? Use. HA + H2O H3O + A to figure out X for H3O and A

22. ## Chemistry

1 g of acid was mixed with 120 ml of distilled water and the solution was filtered into a clean dry beaker. A 25 ml aliquot of this solution was titrated with 0.1120 M NaOH. The pH of the acid was recorded to be 4.42. Calculate the initial concentration of

23. ## chem

Can someone please help me by explaining and correcting me? 1) A 0.057M solution of a weak acid has a pH of 4.93. Determine the ionization constant, Ka, of the acid. a) 2.1 x 10^-4 b) 2.4 x 10^-9 c) 4.1 x 10^-8 d) 2.8 x 10^-7 e) 1.4 x 10^-10 -- To be

24. ## chemistry

Can someone please explain how to do this question? A 0.057M solution of a weak acid has a pH of 4.93. Determine the ionization constant, Ka, of the acid. a) 2.1 x 10^-4 b) 2.4 x 10^-9 c) 4.1 x 10^-8 d) 2.8 x 10^-7 e) 1.4 x 10^-10 -- Well, to be honest, I

25. ## chem

What is the strongest acid among the following? a. CH3COOH b. (Cl)CH2COOH c. (Cl)2CHCOOH d. (Cl)3CCOOH isnt it the most electronegative if the oxygens are the same? The strength of an organic acid depends on the degree of ionization. The chloride end

26. ## chemistry

A 1.0 M acetic acid solution (CH3COOH, pKa = 4.7) is neutralized by dissolving NaOH(s) (a strong base) in the solution. Estimate the pH at the equivalence point of the neutralization process: 4.7 7.0 9.3 Which one of the following statements best explains

27. ## chemistry

do we have buffering region and ph=pka in any of these conditions: strong base vs strong acid strong base vs weak acid weak base vs strong acid weak base vs weak acid

28. ## chemistry

Calculate the percent ionization of a .31 molar solution of acetic acid. The ionization constant of acetic acid is 1.8 x 10^-5

29. ## Chemistry

The weak acid HQ has a pKa of 4.89. calculate the [OH-] of .50 M HQ.

30. ## chemistry

A student prepared a .10M solution of acidic acid. Acidic acid has a Ka of 1.75 x 10-3. What are the hydronium ion concentration and the PH of the solution? I think the PH is 1.76 because I hit -log(1.75 x 10-3) on my calculator and that's what I got

31. ## college-chemistry

calculate the ph of a buffer solution prepared by adding 0.397 mole of the sodium salt of a weak organic acid HA to 0.474 L of 1.023m acid HA with pka=4.82 and diluting to 1.00 L WITH WATER

32. ## Chemistry-Dr Bob help!!

0.100 M solution of a weak acid, HX, is known to be 15% ionized. The weak acid has a molar mass of 72 g/mol. 1. What is Ka for the weak acid? 2. What is the pH of the buffer prepared by adding 10.0 g of the sodium salt of the acid (NaX) to 100.0 mL of

33. ## chemisty

0.100 M solution of a weak acid, HX, is known to be 15% ionized. The weak acid has a molar mass of 72 g/mol. 1. What is Ka for the weak acid? 2. What is the pH of the buffer prepared by adding 10.0 g of the sodium salt of the acid (NaX) to 100.0 mL of

34. ## CHEMISTRY FOR DR. BOB or anyone else

A hypothetical weak acid HA, was combined with NaOH in the following proportions: 0.20 mol HA, 0.08 mol NaOH. The mixture was then diluted to a total volume of 1L, and the pH measured. (a) If pH=4.80, what is the pKa of the acid (b) how many additional

35. ## chemistry

What is the ionization constant of a weak acid with pKa = 8.0?

36. ## CHEMISTRY

7. At pH 7.4 a weak organic acid with a pKa of 6.4 would be 60% ionized % Ionization =[(H^+)/(acid)]*100 = 3.98 x 10^-8 HA ==> H^+ + A^ K = (H^+)(A^-)/(HA) K = (H^+)(A^-)/[HA-(H^+)] Plug in 3.98E-7

37. ## Chemistry

Part A: Unknown Acid use 1gram and mix with 120 mL of distilled water Determine the concentration of the acid by titrating with 0.0998 M of NaOH Concentration of NaOH= 0.0998M Volume of NaOH= 3.5 mL # moles of NaOH= Initial Concentration of Weak Acid- Show

38. ## chemistry

You need to determine the pKa of a weak, monoprotic acid. You add 0.500 moles of the acid to 1.00 L of water. The resulting pH was 1.87. What is the pKa of this weak acid? You may ignore the autoionization of water. 2.74 3.43 5.38 2.01 1.87

39. ## chem

When 0.285 g of a solid weak acid HA (molar mass = 184 g mol−1) is dissolved in water to a total volume of 25.0 mL, the pH of the solution is 3.59. What is the acid ionization constant (Ka) of the acid?

40. ## Plz -- Chem Help

Question.. Nicotinic acid (niacin) is a monoprotic acid with the formula HC6H4NO2. A solution that is 0.012M in the nicotinic acid has a pH of 3.39 at 25C. what is the acid-ionization constant, Ka and pKa for this acid at 25C? Attempt.. HC6H4NO2 C6H4NO2- +

41. ## chem

A weak acid, HA, has an ionization constant of 9.29 x 10-6. If we prepare a solution that is 0.727 M in HA what percent of the acid will be ionized?

42. ## chem

A weak acid, HA, has an ionization constant of 4.34 x 10-8. If we prepare a solution that is 0.273 M in HA what percent of the acid will be ionized

43. ## Chemistry

A 0.23 M solution of a weak acid has a pH of 2.89. What is the Ka(acid ionization constant)for this acid?

44. ## Chemistry

A 0.23 M solution of a weak acid has a pH of 2.89. What is the Ka(acid ionization constant)for this acid?

45. ## biochemistry

A weak base has pKb = 9.25.. A. Calculate the % ionization at pH = 8.25 B. Calculate the % ionization at pH = 10.25 C. What is the pH when 50% of the weak base is ionized?. Is calculating ionization for pkb the same as pka? How do I go about doing it?

46. ## Chemistry

The pH of a weak monoprotic acid, HA, is 4.55. It took 39.22 ml of 0.2334 M NaOH to titrate 25.00 ml of the acid. a. Write an equation for the above reaction. b. Calculate the molarity of the weak acid c. Write the equilibrium equation. Construct a table

47. ## chemistry

how do you write the ionization reaction and the acid ionization constant expression for the third ionization of phosphoric acid in water? Can you explain the main concepts that are involved in this?

48. ## Chemistry

What is the ionization constant for a weak acid HA that is 1.60% ionized in 0.095M solution?

49. ## Chemistry

I took 25 mL of an unknown weak acid and added it to 10 mL of NaOH solution. I measured the pH and got 2.88 with concentration of NaOH @ .0098 and weak acid at 0.0102. What is pKa for the acid?

50. ## chemistry

hello, I can't seem to solve this question. i tried to look up someone else who may have asked this question. I found this girl named Sara,but her answer didn't really help me much because it did not answer the question. What is the pH when enough 0.10 M

51. ## CHEMISTRY

Strong base is dissolved in 675 ml of 0.200 m weak acid (ka=3.25x10^-5) to make a buffer with a ph of 3.95. Assume that the volume remains constant when the base is added. HA + OH ---> H2O + A^- calculate the pka value of the acid and determine the number

52. ## chemistry

hello, I can't seem to solve this question. i tried to look up someone else who may have asked this question. I found this girl named Sara,but her answer didn't really help me much because it did not answer the question. What is the pH when enough 0.10 M

53. ## Chemistry

Strong base is dissolved in 535 mL of 0.200 M weak acid (Ka = 3.16 × 10-5) to make a buffer with a pH of 4.04. Assume that the volume remains constant when the base is added. HA (aq)+ OH^-(aq) -> H2O(l) + A^-(aq) Calculate the pKa value of the acid and

54. ## chemistry

A 0.185 M solution of a monoprotic acid has a percent ionization of 1.55%. Determine the acid ionization constant (Ka) for the acid.

55. ## chemistry

For a week acid whose ionization constant is 1.75 x 10(-5), the pH of its solution is 3.0. Determine its degree of ionization and its percent ionization.

56. ## Chemistry

Determine the equilibrium constant for a 0.10M phenol (HC6H5O) solution that has a pH of 5.43 at 25 degrees C. What is the degree of ionization of this weak acid? Why is the pH value important for this problem?

57. ## chemistry

Can you tell if I'm correct. Which combination in titration has ph=pka and buffer region strong acid-strong base- no to both strong acid-weak base- yes to both weak acid-strong base- yes to both weak acid-weak base- I'm not sure about this one. Can anyone

58. ## chemistry

Can you tell if I'm correct. Which combination in titration has ph=pka and buffer region strong acid-strong base- no to both strong acid-weak base- yes to both weak acid-strong base- yes to both weak acid-weak base- I'm not sure about this one. Can anyone

59. ## Chemistry

Pyridine, a substance used as a catalyst in some synthetic reactions is a very weak base its degree of ionization is equal to 0.03% in solution 0.02 mol L -¹. Determine the ionization constant.

60. ## CHEMISTRY

Strong base is dissolved in 675 ml of 0.200 m weak acid (ka=3.25x10^-5) to make a buffer with a ph of 3.95. Assume that the volume remains constant when the base is added. HA + OH ---> H2O + A^- calculate the pka value of the acid and determine the number

61. ## Chemistry

Provide equations for each of the following: a. Dissociation of a strong base in water solution b. Ionization of a strong acid in water solution: c. Ionization of a weak acid in water solution: d. Ionization of a weak base in water solution: e.

62. ## organic chem

. Use the Henderson-Hasselbach equation: pH = pKa + log [A-]/[AH], where A- is the conjugate base and AH is the weak acid. Calculate the pH of an acetate buffer in which the acetate concentration [CH3COO-] is 3.5 times greater than acetic acid [CH3COOH].

63. ## Plz -- Chem Help

Posted by Rushi on Sunday, March 15, 2009 at 3:35pm. Question.. Nicotinic acid (niacin) is a monoprotic acid with the formula HC6H4NO2. A solution that is 0.012M in the nicotinic acid has a pH of 3.39 at 25C. what is the acid-ionization constant, Ka and

64. ## org. chem

How to start these problems out: Please help thank you Use the Henderson-Hasselbach equation: pH = pKa + log [A-]/[AH], where A- is the conjugate base and AH is the weak acid. Calculate the pH of an acetate buffer in which the acetate concentration

65. ## Stupid Chemistry

Ok, blonde moment here, Kb is the same as Ka but just for bases and Ka is for acids correct? right. Ka is the ionization constant for acids, Kb is the ionization constant for bases. BUT, we can change one into the other this way. KaKb = Kw. So if you are

66. ## Biochemistry

Show Calculations used in mkaing 250mL of 0.5M sodium acetate ph 4.7. You are given: 1M acetic acid (weak acid) 1M sodium hydroxide (strong base) Sodium acetate buffer: ph 4.7 acetic acid pKa: 4.7 So far this is what I've gotten: pH = pKa + log (A-/HA-)

67. ## Chemistry

The Ka of a monoprotic weak acid is 3.39 × 10-3. What is the percent ionization of a 0.125 M solution of this acid? I just do not know where to even start...

68. ## Chemistry

The Ka of a monoprotic weak acid is 8.11 x 10 ^ -3. What is the percent ionization of a 0.125M solution of this acid?

69. ## Chemistry

The Ka of a monoprotic weak acid is 2.04 × 10-3. What is the percent ionization of a 0.181 M solution of this acid?

70. ## Chemistry

The Ka of a monoprotic weak acid is 3.29 × 10-3. What is the percent ionization of a 0.176 M solution of this acid?

71. ## Chem!

does the addition of a strong acid increase the percent ionization of a weak acid HB?

72. ## Chemistry

The Ka of a monoprotic weak acid is 4.47 × 10-3. What is the percent ionization of a 0.184 M solution of this acid?

73. ## Chemistry pH

A 0.60 M solution of a weak acid, HA, has a pH of 3.72. What is the percentage ionization of the acid? What is the value of Ka for the acid?

74. ## Chemistry

A 0.60 M solution of a weak acid, HA, has a pH of 3.72. What is the percentage ionization of the acid? What is the value of Ka for the acid?

75. ## Chemistry

In a solution of a weak acid and its conjugate base, which condition has to be true for pH to equal pKa? The concentration of acid has to be greater than the concentration of base. The concentration of acid has to be equal to the concentration of base. An

76. ## Chemistry

Phenolthalein is a weak acid, explain what it means to be a weak acid and look up phenolthalein’s pKa.

77. ## chemistry

Find a pH of a 0.100 M solution of the weak acid HA. The pKa for the acid 5.0

78. ## Chemistry

Why do we assume 100% ionization for acetic acid (a weak acid)? This is a titration problem. The titrant is sodium hydroxide, if that helps.

79. ## Chemistry

0.2 moles of NaOH were added to a solution containing 0.4 moles of a weak acid and 0.4 moles of its conjugate base. After mixing, the pH of the solution was found to be 5.24. What is the pKa of the weak acid?

80. ## CHEMISTRY

calculate the ionization constant of the conjugate base for a solution made from 0.2Molar HC2H3O2 and 0.5Molar C2H3O2.The ionization constant for the acid (HC2H3O2) IS 1.8 Multiplied by 10^(-5)

81. ## chemistry

What is the pH of a buffer solution made from 0.20M HC2H3O2 abd 0.5M C2H302^-.The ionization constant of the acid (Ka)(HC2H3O2)is 1.8multiplied by 10^-5. (ii)Calculate the ionization constant of its conjugate base

82. ## chemistry

what is the ionization reaction and acid ionization constant expression for the HS- ion in water?

83. ## Chem

Methylaime, CH3NH2. If a 0.100 mol/L solution of methyamine has a pH of 11.80, calculate the ionization constant for the weak base. What is an ionization constant. Is it just K? This is what I did so far: 11.80 = -log (concentration of h3o+) 10^-11.80 =

84. ## Chemistry

Which solution will have the lowest pH? a. 0.10 M HClO2, pKa = 1.96 b. 0.10 M HCN, pKa = 9.21 c. 0.10 M HF, pKa = 3.19 d. 0.10 M HClO, pKa = 7.538 e. 0.00010 M HCl Does the lower the pka stronger the acid, means the lower the ph, so the answer is A?

85. ## Chemistry

the weak acid HQ has a pKa of 4.89. calculate the [OH-] of .85 M HQ.

86. ## Chemistry

PLEASE HELP!! 40 mL of 0.1 M solution of a weak acid (adjusted to a pH of 7.75) is titrated with 0.2 M HCl to a final pH of 2.1. Once the pH of the weak acid reaches 2.1, it is then titrated with 20 mL of 0.25 NaOH. What is the final pH of the solution?

87. ## CHEMISTRY FOR DR. BOB or anyone else

A hypothetical weak acid HA, was combined with NaOH in the following proportions: 0.20 mol HA, 0.08 mol NaOH. The mixture was then diluted to a total volume of 1L, and the pH measured. (a) If pH=4.80, what is the pKa of the acid (b) how many additional

88. ## Chemistry

A weak acid HA (pka=6.00) was titrated with 1.00M NaOh. The acid solution had a volume of 100ml and a concentration of .100M. Find the pH at the following volumes of added base. Vb=20ml

89. ## Chemistry

Need help with AP chemistry, specifically Acids and Bases The acid ionization constant, Ka, for propanoic acid, C2H5COOH, is 1.3  10 -5 . (a) Write the expression for the acid-dissociation constant, Ka for propanoic acid. (b) Calculate the hydrogen ion

90. ## college chemistry

In the analysis of food, the nitrogen from the protein is sometimes converted into ammonia which is titrated against a strong acid. Given that the final NH3 concentration (approximate) is 0.2M and that pKa for NH4+ is 9.2, choose the best indicator for

91. ## CHEMISTRY

In the analysis of food, the nitrogen from the protein is sometimes converted into ammonia which is titrated against a strong acid. Given that the final NH3 concentration (approximate) is 0.2M and that pKa for NH4+ is 9.2, choose the best indicator for

92. ## chemistry

In protein precipitation, two liters of 5mM buffer solution with pH 5.2 is needed in the isolation of albumin. Which among the buffer solutions is best fitted for the said purpose?justify your answer. a. acetate buffer with pka=4.73? b. tris-aminomethane

93. ## chemistry

7. At pH 7.4 a weak organic acid with a pKa of 6.4 would be ionized at what percent?

94. ## chemistry

The weak acid HQ has pKa of 4.89. Calculate the [H3O+] of .025 M HQ. when i did this i got 5.2 x 10 ^-14

95. ## chem

7. At pH 7.4 a weak organic acid with a pKa of 6.4 would be ionized at what percent?

96. ## chem need assistance

7. At pH 7.4 a weak organic acid with a pKa of 6.4 would be ionized at what percent?

97. ## chemistry

7. At pH 7.4 a weak organic acid with a pKa of 6.4 would be ionized at what percent?

98. ## chemistry

7. At pH 7.4 a weak organic acid with a pKa of 6.4 would be what percent ionized.

99. ## chemsitry

The weak acid HQ has pKa of 4.89. Calculate the [H3O+] of .035 M HQ. Thanks.