Which element is the reducing agent in this reaction? 2kmno4+3na2so3+h2o→2mno2+3na2so4+2k oh

Hi, this one is a redox reaction. which mean here substances have oxidized and reduced at the same time. When redox reactions happens the oxidation number of elements which participate for reaction change. 

Here, oxidation no.of Mn and S has changed. It means one out of (MnO4)-ion or (SO3)2- ion has either oxidised or reduced.

oxidizing no. of Mn in(MnO4)- ion has decreased from +8 to +4

oxidizing no. of S in SO# ion has increase from 4 to 6

So MnO4 has reduced. This means that the reducing agent is the (SO3)- ion

2.00 is the !

Iwould you figure it out but you don't have a picture or in your question as to what the physical property you're looking for is