Question

Calculate the concentration of all species in a 0.220 molL−1 C6H5NH3Cl solution. (Kb for C6H5NH2 is 7.50×10−10.)

Find [C6H5NH3+], [Cl−], [C6H5NH2], [H3O+], [OH−]

Answer 1

The given reaction is as follows: CHÚNH +H2O=C,H,NH +H,0" Construct the ICE table for the reaction as follows: C,H, NH +H,0,-C,H,NH; +H20* Initial 0.220 Change - x + x + x Eq" 0.220 - x The K, for the given reaction is written as follows: K - [C,HNH2] H307 [C,H, NH] K, X K, 0.220 - x 1.0x10-14 x 7.5x10-10 0.220 - x 1.3x10-$ (0.220 - x) = x2 0.286x10-5 -1.3x10-> x= x?

x=0.00168 Calculate the pH of the solution as follows: pH =- log[H] =-log(0.00168) = 2.77 Calculate the pOH of the solution as follows: pH + pOH = 14 pOH = 14 -pH = 14 -2.77 =11.23 Therefore, the pOH of the solution is 11.23). Calculate the concentration of hydroxide as follows:

pOH = -log[pH] 11.23= -log[pH] [OH-] =10–11.23 [OH ]=5.88x10-12 The concentration of all of the species are as follows: [CHNH]=0.220 x = 0.220 -0.00168 = 0.218 M [C,H, NH]=x = 0.00168 M [H20"]= = 0.00168 M [OH-] = 5.88x10-6 M