Balancing equations

[Violet]

Hi, I am a student taking Chemistry at GCSE standard, and I have some problems with these equations for hw:

The hw states :
Balance these equations:

a) NH3 + O2 + H2O --> HNO3

b) PB(NO3)2 --> PBO2 + NO2 + O2

c) AL + HCL --> ALCL3 + H2

d) C2H5OH + O2 --> CO2 +H20

e) NA2CO3 + HCL --> NACL + H20 + CO2

I wonder if you could give me some help here please. Some pointers would be appreciated.