I need help with some Chemistry?

[Juno]

1. What is the oxidation number for Carbon in CO2? [- Is it 0?]

2. What is the oxidation number for sulfur in H2SO4? [Is it 0?]

3. What is the oxidation number for manganese in MnO4^- ?

4. What is the oxidation number of each element in KNO3?

5. What is the oxidation number of each element in SO4^2- ?


-Thanks to all who helped, I really appreciate it.

 

[poysunut2001]

1. C is +4 each O is -2 such that 4(1) + 2(-2) = 0
2. S is +6, H +1, and O -2
3. Mn is +7
4. O is -2, K is +1, N is +5
5. S is + 6 and O is -2