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The base-dissociation constant, Kb , for aniline, C6H5NH2,  is 4.0 x 10-10. The acid-dissociation constant, Ka , for the anilinium ion, C6H5NH3+, is                     .   Hint: All Ka/Kb values are at 25°C.

Consider the titration of 10.0 mL of 0.10 M HClO4 with KOH.   What is the pH after 20.0 mL of 0.35 M KOH has been added?

Complete and balance the following redox half-reaction equation under acidic conditions.     Cr3+(s)   →   CrO42-(aq)       (acidic solution) How many electrons are transfered in this half-reaction when the equation is balanced using the set of smallest whole-number coefficients? 

Consider the following titration curve graphs:   Which plot shows the pH curve expected when HCN is titrated by NaOH ?

Consider the titration of 50.0 mL of 0.10 M HClO4 with KOH.   What is the pH after 20.0 mL of 0.50 M KOH has been added?

Copper metal, Cu (s), is produced by running a current through a solution of Cu2+ in an electrolytic cell. How many grams of copper metal can be deposited from Cu²⁺(aq) when a current of 2.50 A is run for 2.00 h? Hint:  F = 96,500 C/mol e− Hint:  1 A = 1 C/s

The diagrams here represent solutions at various stages in the titration of a weak base B (such as NH3) with HCl. Which image best represents the solution beyond the equivalence point?             

Given the two following reduction half reactions: Fe3+(aq) +  e- →  Fe2+(aq)                  Eo = +0.770 V Pb2+(aq) +   2 e- →   Pb (s)                  Eo = −0.13 V Calculate ΔGº (in kJ) for a Fe2+/Pb voltaic cell. Hint:  Remember that a voltaic cell runs on a spontaneous redox reaction.  Hint: Make sure to determine the total moles of electrons transferred for the cell.

At 25°C, the pH of a solution is 7.23.  What is the hydroxide ion concentration, [OH−], of this solution?  

Which of the following has the smallest standard molar entropy, S° (298.15 K)?