Untitled - Kelly Walsh High School

70 CHEMISTRY FOR THE UTTERLY CONFUSED
Mg(s) 2 HC 2H 3O 2(aq) l Mg 2 (aq) H 2(g)
Al 2(SO 4) 3(aq) Fe(s) l NR
2 Li(s) 2 H 2O(aq) l 2 Li (aq) H 2(g)
Completing the reactants requires the addition of the following ions: reaction 1,
2 Cl ; reaction 2, 2 Br ; reaction 3, 2 C 2H 3O 2 ; reaction 4, no ions; reaction 5, 2
OH . To balance the reactions we add these ions to the other side of the reaction
arrow and combine with the cations present on the other side. This gives
the molecular equations.
Ni(s) 2 HCl(aq) l NiCl 2(aq) H 2(g)
Zn(s) CuBr 2(aq) l ZnBr 2(aq) Cu(s)
Mg(s) 2 HC 2H 3O 2(aq) l Mg(C 2H 3O 2) 2(aq) H 2(g)
Al 2(SO 4) 3(aq) Fe(s) l NR
2 Li(s) 2 H 2O(aq) l 2 LiOH(aq) H 2(g)
We can now follow the steps used previously to convert each of these to a total
ionic equation:
Ni(s) 2 H (aq) 2 Cl (aq) l Ni 2 (aq) 2 Cl (aq) H 2(g)
Zn(s) Cu 2 (aq) 2 Br (aq) l Zn 2 (aq) 2 Br (aq) Cu(s)
Mg(s) 2 HC 2H 3O 2(aq) l Mg 2 (aq) 2 C 2H 3O 2 (aq) H2(g)
Al 2(SO 4) 3(aq) Fe(s) l NR
2 Li(s) 2 H 2O(aq) l 2 Li (aq) 2 OH (aq) H 2(g)
Finally, we eliminate the spectator ions to obtain the net ionic equations:
Ni(s) 2 H (aq) l Ni 2 (aq) H 2(g)
Zn(s) Cu 2 (aq) l Zn 2 (aq) Cu(s)
Mg(s) 2 HC 2H 3O 2(aq) l Mg 2 (aq) 2 C 2H 3O 2 (aq) H2(g)
Al 2(SO 4) 3(aq) Fe(s) l NR
2 Li(s) 2 H 2O(aq) l 2 Li (aq) 2 OH (aq) H 2(g)
4-6 Utterly Confused About Titrations
A common laboratory application of acid-base reactions is titration. A titration
is a laboratory procedure in which we use a solution of known concentration to
determine some information (such as concentration and mass) about an
unknown substance. A titration may involve any type of reaction—acid-base,
redox, and so on. In this section, we will only consider acid-base titrations. The