1. Questions

chemistry

A. Strong Base

1.) What is the concentration of a solution of KOH for which the pH is 11.89?

2.) What is the pH of a 0.011M solution of Ca(OH)2?

B. Weak Acid

1.) The pH of a 0.060M weak monoprotic acid HA is 3.44. Calculate the Ka of the acid.
2.) The pH of 0.100M solution of weak monoprotic acid HA is 2.85. What is the Ka of the acid?

C. SALT HYDROLYSIS
1.) Calculate the pH of a 0.24M sodium formate (HCOONa) solution. Kb=5.9x10^-11.
2.) Calculate the pH of 0.25M pyridium chloride (C5H5NHCl)solution. Ka=5.9x10^6.

D. COMMON ION EFFECT
1.) What is the pH of a solution that is 0.30M in HCOOH and 0.52M in HCOOK.
Ka of HCOOH=1.7x10^-4.
2.) Calculate the pH of a buffer system containing 1.0M CH3COOH and 1.0M CH3COONa. Ka of CH3COOH=1.8x10^-5.

Please help.... i do not know what to do....

  1. 👍
  2. 👎
  3. 👁
  4. ℹ️
  5. 🚩
jaycab

  1. Please do not put long lists of questions as it is unlikely that they will all get answered. Have you had go at answering any of them?

    1)
    if pH =11.89 then
    pOH=14-11.89=2.11

    (this assumes that Kw=10^-14, i.e. that the solution is at ca 25C)

    [OH-]=10^-pOH

    2)
    if concentration is 0.011M then the OH- concentration is twice this as each mole of CaOH2 yields two moles of OH-

    so[OH-]=0.022M

    pOH=-log([OH-]/mole litre^-1)

    then pH=14-pOH
    (same assumption as above)

    B
    1)
    HA<-> H+ + A-
    at start
    0.060M
    at equilibrium
    0.06-x x x

    if pH=3.44 then x=[H+]=10^-3.44

    Ka=[H+][A-]/[HA]
    so
    Ka=x^2/(0.06-x)

    find Ka

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
    Dr Russ

  2. i need answer

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
    obed

Respond to this Question

First Name

Your Response

Similar Questions

  1. CHEMISTRY

    HOW CAN U TELL IF HNO3 +KNO3 IS A BUFFER SOLUTION A buffer solution must contain a weak acid and its conjugate base OR a weak base and its conjugate acid. HNO3 is a strong base and KNO3 is the salt of a strong base (KOH) and a

  2. 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

  3. Chemistry

    Select the statements that correctly describe buffers.? 1) The pH of a buffer solution does not change significantly when any amount of a strong acid is added. 2) The Ka of a buffer does not change when any amount of an acid is

  4. chem class

    A 25.00-mL sample of 0.723 M HClO4 is titrated with a 0.273 M KOH solution. The H3O+ concentration after the addition of 10.0 mL of KOH is ???? M.

  1. chem

    Why was a strong base (KOH) used in the synthesis of ferrocene? Why would a strong acid not be a suitable alternative?

  2. AP Chemistry

    Rank these compounds in order of increasing hyroxide ion concentration: weak base, weak acid, strong base, strong acid.

  3. Chemistry

    Which of the following statements are true about a strong base and a weak base at a pH of 11? A) HCl will not bring the pH of either solution to pH 7. B) Both bases require the same amount of HCl to reach pH 7 because they are

  4. 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

  1. Chemistry

    A base has a Kb of 2.5 x 10–11. Which of the following statements is true? This is a concentrated base. This base ionizes slightly in aqueous solution. This is a strong base. An aqueous solution of this base would be acidic.

  2. Chemistry

    A 25.00-mL sample of an H2SO4 (2 and 4 are subscripted) solution of unknown concentration is titrated with a .1328 M KOH solution. A volume of 38.33 mL of KOH was required to reach the endpoint. What is the concentration of the

  3. Chemistry

    Calculate the pH for each of the following cases in the titration of 50.0 mL of 0.140 M HClO(aq) with 0.140 M KOH(aq).HClO is a weak acid with a Ka of 4.0× 10–8. It reacts with strong base to produce ClO–. (e) after addition

  4. Chemistry

    Calculate the molarity of the following solutions: 5.0g of KOH in 4.0L of KOH solution I went from grams of KOH to moles of KOH to molarity but still got the wrong answer... 5.0g KOH X 1 mol KOH/56.108g KOH = 5.0 mol

View more similar questions or ask a new question.