Question

Balanced equations..done?
Is each reaction a redox reaction? For those reactions that are redox reactions, I must identify the substance being oxidized and the substance being reduced...
(a) Zn(s) + CoCl2 (aq) ---> ZnCl2 (aq) + Co(s)
(b) HI(aq) + NaOH(aq) ---> H2 O(l) + NaI(aq)
(c) AgNO3 (aq) + NaCl(aq) ---> AgCl(s) + NaNO3 (aq)
(d) 2 K(s) + Br2 (l) ---> 2 KBr(s)

Answer 1

You need three things:
a. What is the change in oxidations state?
b. Were electrons lost of gained.
c. the definitions: oxidation is the loss of electrons.
Reductions is the gain of electrons.

Here is a.
Zn has an oxidation state of zero on the left and +2 on the right. Loss of electrons. oxidation.
Co is +2 on the left and zero on the right. Gain of electrons. Reduction.