[chris]

 ???I need to know step by step on how to balance the equation As2+HNO3+H2O=H3AsO4+H2SO4+NO
Thanks

[kevins]

please check the equation again?

because I can't find the Sulphur at the left hand side.

[ssssss]

please check the equation again?

because I can't find the Sulphur at the left hand side.

I think sulphur is supposed to be with Arsenic.

[AWK]

As2S5+HNO3+H2O=H3AsO4+H2SO4+NO
15S(-2) =  S(+6) + 120e
40N(+5) + 120e = 40N(+2)
3As2S5 + 40HNO3  + 4H2O = 6H3ASO4 + 15H2SO4 + 40NO

As2S3+HNO3+H2O=H3AsO4+H2SO4+NO
6As(+3) + 9S(-2) = 6As(+5) + 9S(+6) + 84e
28N(+5) + 84e = 28N(+2)
3As2S3 + 28HNO3  + 4H2O = 6H3ASO4 + 9H2SO4 + 28NO

Note - reaction with HNO3 with evolving NO produce elemental S instead of H2SO4.
Yoy can oxidize S to H2SO4 using hot concentrated HNO3 and then NO2 is produced.