Explore BrainMass
Share

Explore BrainMass

    Acid, Bases, Equilibria Questions

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    1) The solvent cation in liquid ethanol, CH3CH2OH, is

    a) CH3CH2O- b) H+ c) CH3CH2OH+ d) CH3CH2OH2+ e) CH3CH2OH-

    Answer _________

    2) Fill in the blanks.

    a) the normality of 0.20M solution of H2SO4 ________________________

    b) The following reaction is best classified as an Arrhenius, Bronsted or Lewis acid base reaction? SiF4 + 2F- --- SiF62- _________________

    c) The conjugate base of H2PO3- _________________________

    d) The conjugate acid of AsH3 _________________________

    3) Identify the correct answer in each case.

    a) The stronger acid, H3SbO3 or H3AsO3 ? _____________________

    b) The stronger base, GeH4 or SiH4 ? ________________________

    c) The stronger acid, H2TeO3 or H2 TeO4 ? _______________________

    d) The stronger base, Pd (OH)2 or Sn (OH)2 ? _________________________

    e) The stronger conjugate acid, the conjugate acid of Cl04- or the conjugate acid of MnO4-? ____________________________

    f) The amphiprotic species in the following equation

    H2CO3 -- H+ + HCO3- _____________________

    g) The conjugate base in the Bronsted - Lowry reaction
    HBr + NH3 - NH4+ + Br- _______________________

    h) The Lewis base in the reaction
    Cu(NO3)2 + 4H2O - Cu(H2O)42+ + 2NO3- ____________________

    4. In a 0.90M solution of the weak acid HA, the acid is 11% ionized. What is the ionization constant, Ka, for the acid? (Show work)

    5. Ka for HC2H3O2 is 1.8 x 10-5. To adjust the pH value of one liter of 0.020M acetic acid to pH = 6.0, one must add how many grams of KC2H3O2? (Show work)

    6. Would the pH of a 0.1M solution of Cs2SO3 be less than, greater than, or equal to 7.0? (Show work)

    7. In the titration of HClO4 with LiOH, 50.0mL of 0.35OM LiOH is added to 30.0mL of 0.400M HCl04. What is the pH at this point in the titration? (Show work)

    8. What is the pH of a buffer made by mixing equal volumes of 0.10M NH3 and 0.10M NH4Cl? Kb for NH3 = 1.8 x 10-5
    (Show work)

    9. What is the pH after this same solution is made 0.020M in KOH? (Show work)

    10. Below a pH of 4.8, an indicator, exists in the blue acid form, HIn. At pH 4.8 about 10% of the indicator exists in the rose base form. What is the ionization constant of this indicator? (Show work)

    © BrainMass Inc. brainmass.com October 9, 2019, 3:48 pm ad1c9bdddf
    https://brainmass.com/chemistry/acids-and-bases/acid-bases-equilibria-questions-13742

    Attachments

    Solution Preview

    1.
    Since it's a cation we know that it has to be positive. It cant be H+ because that would be of water. Cant be the negatively charged ones, and it cant be Ch3Ch2OH+ because that compound is uncharged. It can only be d

    2.
    a. The normality is similar to molarity/. However it depends on the number of "equivilant" H+'s . for H2SO4 we know that there are 2 H+ that can be used as acid. So we can say that Normality=Molarity x p (p here is 2, in HCl for instance p would be one because of only one H)
    b. there is donation/taking of electrons. We know the bronted definition says that its an H+ donor or taker. Lewis is the one that deals with electron exchange
    c. the conjugate base means the basic form of the compound. i.e more basic than what we have. H2PO3- conjugate base would be one with one less proton. Which is HPO3-2
    d. conjugate acid means more acidic version. For AsH3 means its will be AsH4+

    3.
    a. elements down a group are more acidic because they have higher polarizability. i.e they have ...

    Solution Summary

    The solution contains a detailed, comprehensive explanation of each of a series of mock test problems concerning acids, bases and equilibria.

    $2.19