Chemistry help?

Question

Balance each half-reaction for atoms and charge.
a) Na->Na+
b)Sn4+->Sn2+
c)Fe2+->Fe3+
d)Cl2->Cl-

Also I need help with matching 5 reactions....

Fe+CuSo4->FeSO4+Cu
CaO+H2O->Ca(OH)2
NH4NO3->N2O+H2O
Ca(OH)2+2HCl->CaCl2+2H2O
C+O2->CO2

A) single displacement reaction
B) decomposition reaction
C) double displacement reaction
D) synthesis reaction
E) combustion reaction



Lastly balancing this equation.
CO2+H2->CH4+H2O


Please help me. I know it may seem like a lot but I dont understand them. I'm doing this as an online test and I really need help I've done majority of my test questions but these. Please help!

I was working on the half balance.. are these right???


a)

b)Sn4+ + 2 e- -----> Sn2+

c)Fe2+ ---> Fe3+ + e¯

d)Cl2 + 2e¯ ---> 2Cl¯

Is this right?

What is the oxidation number of K in KClO4?

+4 (this one)
-1
+2
+1
-7 (someone said its this one but Im not sure)

Answer 1

For the first three half reactions, you only need to add electrons to balance the charges: a) add one e- on the right side of the arrow. b) add 2e- on the left of the arrow. c) add one e- on the right side of the arrow. d) 2Cl + 2e- -> 2Cl-.

The last of the five reactions is E) combustion reaction because you are burning carbon in oxygen. The first of the five is the A)single displacement reaction. You are displacing the copper with the iron. The second reaction is D) the synthesis reaction. You are making one compound from two. The third reaction is B) decomposition reaction. You are breaking a larger compound molecule into two smaller compound molecules. That leaves the fourth reaction as C) double displacement reaction.

Answer 2

alright heres the last balanced equation. but you really need to understand how to do this yourself. these are really simple once you understand the process

CO2 +4H2 == CH4 +2H20

assuming normal subscripts.