Chem101
4.16 Specify what ions are present upon dissolving each of the following substances in water:
a) MgI2(aq) -> Mg 2+ (aq) +2OH-(aq)
b) Al(NO3)3(aq) -> Al3+(aq)+3NO3- (aq)
c) HCLO4(aq) -> H+ (aq) + ClO4- (aq)
d) NaCH3COO(aq) ->Na + (aq) + CH3COO-(aq)
4.22) In each reaction, the precipitate is in bold type.
a) Ni(NO3)2 (aq) +2NaOH (aq) ->+2NaNO3(aq) + NiOH2 (s) b )No precipate, therefore, no reaction.
c) Na2S(aq) + CuCH3COO (aq) -> CuS(s) + 2NaCH3COO (aq)
4.24) Write balanced net ionic equations & Identify spectator ion or ions in each reaction.
a) 2Cr3+ (aq) +3CO32-(aq) -> Cr2(CO3)3(s) ,spectators: NH4,SO42-
b) Ba2+(aq) + SO42-(aq) ->BaSO4(s), spectators: K+, NO3-
c) Fe 2+ (aq) +2OH- (aq)-> Fe(OH)2(s), spectators: K +, NO3-
4.38) classify each of the following aqueous solutions as a nonelectrolyte, week, or storng.
a)strong electrotlye b) Strong electrolyte C) strong (NH4Cl)
d) none ( CH3COCH3 : acetone) e) strong CoSO4 f) none (sucrose)
4.44) K2O (aq) + H2O (l) -> 2KOH(aq), molecular; 2K + + O2- +H2O (l) ->2K + + 2OH-
Ionic: O2- (aq) + H2O(l) -> 2OH- (aq), net ionic base: (H+ ion acceptor ) O2- (aq); acid ( H + ion donor) H2O (aq); spectator: K +
4.50 Determine the oxdation number for the indicated elment .
a) Ti in TiO2 : +4 x +(2*2) = 0 , x = 4
b)Sn in SnCl3- : +2 x +( 3* -1 = -1 x=2
c)N in N2H4 : -2 = 2x + 4(1) = 0 x = -2
d) C in C2O4 -2 : +3 2x + (-2) 4 = -2 x= 3
e)N in HNO2): +3
f) Cr in Cr2O72- +6
4.56) a) Mn(s) + NiCl2 (aq) -> MnCl2((aq))+Ni(s)
b) Cu(s) + Cr(C2H3O2) (aq)-> NR
C) 2Cr(s)+ 3NiSO4(aq) -> Cr2(SO4)3(aq)+ 3Ni(s)
d) Pt(s) + HBr(aq) -> NR
e) H2 (g) + CuCl2 (aq) -> Cu(s) + 2HCl (aq)
4.64)
Calculate the mol of Na + at the two concentrations; the difference is the mol NaCl required to increase the Na + concentration to the desired level.
0.118mol/L *4.6L =