Properties of Solutions

 

28) (a) m = 15.0 g Al2(SO4)3

            V = 0.350 L

 

            Al2(SO4)3(s) 2Al3+(aq) + 3SO42-(aq)

            [Al2(SO4)3] = n/V = 15.0 g Al2(SO4)3 x 1 mol Al2(SO4)3/342.14 g Al2(SO4)3/0.350 L

            [Al2(SO4)3] = 0.125 M

 

      (b) m = 5.25 g Mn(NO3)2·2H2O

            V = 175 mL

 

            Mn(NO3)2·2H2O(s) Mn2+(aq) + 2NO3-(aq) + 2H2O(l)

            [Mn(NO3)2·2H2O] = n/V = 5.25 g Mn(NO3)2·2H2O x 1mol Mn(NO3)2·2H2O/215.00 g Mn(NO3)2·2H2O/(175 mL x 1 L/103 mL)

            [Mn(NO3)2·2H2O] = 0.140 M

 

      (c) [H2SO4] = 9.00 M

           Vc = 35.0 mL

           Vd = 0.500 L

 

            H2SO4(aq) H+(aq) + HSO4-(aq)

            nc = nd

            [H2SO4]c x Vc = [H2SO4]d x Vd

            [H2SO4]d = [H2SO4]c x Vc/Vd

            [H2SO4]d = 9.00 M x 35.0 mL x 1 L/103 mL/0.500 L = 0.630 M