Question

Sodium Azide, (NaN3), the conjugate base of hydrazoic acid, is sometimes added to water to kill bacteria. Given a 0.010 M solution of sodium azide,
A) What is the [H+] concentration from the Azide base rxn?

B) Given a 0.01 M NH4+, what is the [H+]?

C) What is the hydrozoic acid (NH3) half cell potential given 1atm N2(g)?

Please show steps

Answer 1

A. One note on this part. NaN3 is NOT the conjugate base of HN3. N3^- is the conjugate base. (NaN3 is the salt of the conjugate base.)
...........N3^- + HOH ==> HN3 + OH-
I........0.01.............0......0
C.........-x..............x......x
E.......0.01-x............x......x

Kb for N3^- = (Kw/Ka for HN3) = (x)(x)/(0.01-x). Solve for x = (OH^-) and convert to H^+.

B. I assume you mean NH4^+ and not ammonium azide. This is done the same way as part A but the hydrolysis is different.
NH4^+ + H2O ==> NH3 + H3O^+
Ka for NH4^+ = (Kw/Kb for NH3) = etc.

C. Can't you find this value in tables?

Answer 2

coppers atomic mass is 63.5 and occurs in nature in the form of twi isotopes Cu-63 abs Cu 65