1. A beaker contains 25.0 mL of 0.80 M propylamine (C3H2NH2; KB=5.1 X 10^-4). a.

Question

1. A beaker contains 25.0 mL of 0.80 M propylamine (C3H2NH2; KB=5.1 X 10^-4). a. Is propylamine classified as a weak or strong,acid or base? Write the equation showing the equilibrium established by propylamine in water. b. Solid C3H7NH3 is added to the 0.80 M C3H7NH2 solution. Write the equation showing the ionization of the C3H7NH3Br. Does this equation proceed 100% to completion? What is the identity of the common ion? c. How does addition of this common ion to the 0.80 M C3H7NH2 affect (Increases,decreases, remains the same) each of the following? Explain. d. Will addition of solid KBr to the 0.80 M C3H7NH2 affect the pH and [H3O+]? Why or why not?

Explanation / Answer

a) PA + H2O <-------> PAH+ + OH- (PA-C3H7NH2)

b) PAHBr + PA + H2O <-----> 2PAH+ + Br- + OH-

this reaction will not complete and the common ion is PAH+, C3H7NH3+

c) addition common ion shifts the reaction towards left hand side. therefore,

[H3O+] increases, pH decreases, [PA] increases, [OH-] decreases and % ionization remains the same as it is related to the dissociation constant.

d) addition KBr will not affect this reaction as KBr and PA have no common ion.

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---