[biospy]

.Balance and identify the species that have been oxidized and the species that have been reduced.
Reaction            
Cl2  +  I-   -->  I2  +  Cl-
WO2  +  H2  ---> W  +  H2O
Ca  +  H2O  -->  H2  +  Ca(OH)2
Al  +  O2   -->  Al2O3

2.   If the following redox reactions are found to occur spontaneously, identify the more active metal in each reaction.

2Li  +  Cu²+  -->  2Li+  +  Cu
 Cr  +  3V³+  -->  3V²+  +  Cr³+
 Cd  +  2Ti³+  -->  2Ti²+  +  Cd²+

[Yggdrasil]

In the future please post your attempt at answering the question (for other forum rules please see http://www.chemicalforums.com/index.php?page=forumrules).

For your first question, you should first assign oxidation numbers to each atom on the reactant side of the equation then see if the oxidation numbers change on the product side.  If the oxidation number is lower the atom was reduced; if the oxidation number is higher, then the atom was oxidized.  If you need help assigning oxidation numbers please see http://www.chembuddy.com/?left=balancing-stoichiometry&right=oxidation-numbers-method

For your second question, the answer can easily be found by reviewing information on the activity series (or reactivity series) either at wikipedia or in your chemistry text.

If you have more questions, we'll be glad to help.  However, in the future please follow the forum rules and show that you have at least attemped to answer the question first (for other forum rules please see http://www.chemicalforums.com/index.php?page=forumrules).

[biospy]

Okay, sorry.

Can I post these answers and you tell me if I did anything wrong then


.Balance and identify the species that have been oxidized and the species that have been reduced.
Reaction           
Cl2  +  I-   -->  I2  +  Cl-
Oxidized: I-
Reduced: Cl2

WO2  +  H2  ---> W  +  H2O
Oxidized: 2H2
Reduced: W

Ca  +  H2O  -->  H2  +  Ca(OH)2
O: Ca
R: H2

Al  +  O2   -->  Al2O3
O: 4Al
R: 3O2

2.   If the following redox reactions are found to occur spontaneously, identify the more active metal in each reaction.

For this, I was just confused at how to tell if they occur SPONTANEOUSLY....wasn't sure if they all did, so these are my answers assuming they do occur spontaneously, but could you explain to me if they don't.
2Li  +  Cu²+  -->  2Li+  +  Cu
2Li more active

Cr  +  3V³+  -->  3V²+  +  Cr³+
Cr more active

Cd  +  2Ti³+  -->  2Ti²+  +  Cd²+
Cd more active