[cluckcluckchuck]

I am having trouble solving this problem.

Sodium azide (NaN₃) is sometimes added to water to kill bacteria.  Calculate the concentration of all species in a 0.010 M solution of NaN₃.  The K_a value for hydrazoic acid (HN₃) is 1.9 * 10^-5.

[Borek]

If you have calculated pH of NaCN solution you should have no problems with this one

[AWK]

NaCN is an another goals of wool. We are talking on sodium azide. Na+ and N3- can be allmost the same as NaN3, and HN3 can be calcualted from hydrolysis and approximately can be as low as 1% of salt concentration.

[Borek]

I was referring to cluckcluckchuck "Another Acid-Base Properties of Salts Problem" post - in both cases calculations are identical (hydrolysis of weak acid salt), just the final pH is different.