Question

For the reaction: PbCl2(s) → Pb2+ (aq) + 2Cl(aq), what is Q* when 5.6 ml of 0.043 M lead nitrate is added to 20 ml of 0.022 M sodium chloride? Ksp of lead chloride is 1.6 x 10-5 M3. Hint given in general feedback "Recall: Q is compared to Ksp to determine whether a precipitate forms. Answer: Answer:

Answer 1

problems Preupitation let us consider a reaction of insoluble or Sparinging soluble salt, Ag cl (s) Ag+ (a + ce 6) Now , Reaction quotient, 9: Tag+] [4] In order to take place precipitate, a) kse Ksp solubility product Precipitation of a takes place Agel. @ • a kse, no precipitation O kse. (Dissolution) system en remains in equilibrium. • solarity = moles per litre of solute prosent Solution. molar concentration's molesot Solute volume e - Asolute of solution solution 7 oriren Problem y first to determine the of pb²t cation and i enough to allow for the pban az insoluble salt concentrations anion, are high formation of precipitates out of solution.

The dissociation of pb (193) can be engressed as pb (Moz) a cat pot (am + 2 Nazcan so one more of Pb(NO3). will give one pb2t cation in Solution istoles made of pb2t present in 5.6 m2 of 0.043 in solution, npizt = ax Upbel & 0.043 mole ( 12 = lorome) - 2.408x154 more 1 x soft Tv Similarly , for race the dissociation can be written as Mad car mat(aq) & cerca so every ray one mole of mach gives one more more of ce- anion in solution. moles of ci- present in some of 0 1022m solution, ha = C x V Nace = 0.022 mole irro Now, - 4.4x10-4 mole total volume of solution, Vsolution - (VPb(NO3)2 + Mace) me - (5.6+20m2 = 25.6 m2

Now, a the the in concentrations of pb²t and resulting Solution win be [Pb2+ ] = - 2.408 no-u. noget more 25.6X163L V solution 9.406 X 10-3 M ha 4.4x10-4 mole and [a] = soluti 75'6X1631 = 0.01718 m 0 The dissociation equilibrium of obele Can be written as, po ela B) Pb²+ (an+ace (ar : Solubility products i Kap = [p62+] [-] 16x105 = [P624] [etja Now reaction quotient, o a = [ Pb2+] [-] = 19.406x103) (0.01718) = 21776 X1056 < 16x105 KSP since, & (ks.. no precipitate win and reaction quotient value 2.776 x 10