Question

Calculate the percent ionization of hydrazoic acid (HN3) in solutions of each of the following concentrations (Ka is given in Appendix D in the textbook). 1.9 * 10^-5

Part A: 0.372 M Express your answer using two significant figures.

Part B: 0.112 M Express your answer using two significant figures.

Part C: 4.31×10⁻² M . Express your answer using two significant figures.

Answer 1

14 Na + H2°* Purt A N, P + H, 0.372 M (initial) 0.37211-4) 0.3720 0.3720 ka = 10.372 *) (0.3720) = 0.37262 0.372 (10) 1-dal (a is very small for weak auida) Giveni ka=1.9x105 1.98.10.5 = 0.3724? 19xlors = 51.1x10-6 - 0.372 da (51.1x1056)"? - 7.15 x 10-3 % ionization of Ngh = xx 100% = 1. 7.15 % 103, 100% = 0.72%

Pond B Ng H + H₂O e Ng + Haut 0.112 M linitial) 0.11211-) 0.1120 0.1122 alide) kas (0.1126) C0.1122) = 0.1120 0.11211-x) 1-241 CL is very small for weak Given: Ka=1.9x10-5 119x105 = 0.1120² x2, 1.axlos = 169.6 8 106 0.112 do (169.6x10-6)= 13.02 X70*3 % ionization of N3M = 4x100 % = 13:02 x 10 X 100% = 1.3%

parte N3M & H₂O E Nå + H₂O* 4.31x10 2 0 0 4:31% 10% -a) 4.31x10*a 4.318 copa KQ = (4.31x 105%) (4.31 x 10') = 4.31x20 de 4.31 x 10211-6) Indal (a is very small for weak acids) Cliveni Ka = 119x10s 1,9x105 = 4.31x10222 x²= 198105 5 = 4.41 x 10y = - 4.31x10m2 d = (4.41 x 10y) = 2.1x1012 % imization of Nal = QX100% = 2.1x10²x 110% = 211%