Question about balancing a reaction

[yuval12]

Homework Statement

balancing a reaction

Relevant Equations

H3PO4(aq) + KMnO4(aq) + H2SO4(aq) → H3PO4(aq) + MnSO4(aq) + K2SO4(aq) + H2O(l)

hi,

I was asked to balance this reaction :

H3PO4(aq) + KMnO4(aq) + H2SO4(aq) → H3PO4(aq) + MnSO4(aq) + K2SO4(aq) + H2O(l)

can I get some help? why we can't balance this reaction? and what can we say about a reaction that has the same compound as a reagent and a product?
thank you

 

[mjc123]

That's not a reaction. Mn is being reduced, but nothing is being oxidised. Have you copied it correctly?

 

[yuval12]

yes, our teacher insists that there is no mistake in the reaction

 

[mjc123]

I assure you there is. What is the permanganate oxidising?

 

[Borek]

You were told exactly the same at other forum, weren't you?

 

[mfb]

Relevant Equations:: H3PO4(aq) + KMnO4(aq) + H2SO4(aq) → H3PO4(aq) + MnSO4(aq) + K2SO4(aq) + H2O(l)

why we can't balance this reaction?

Ignoring H3PO4(aq) which needs to stay balanced (only chemical with P) you have five elements, K, Mn, H, S, O, that have to match on both sides -> 5 equations. You have five chemicals there, which gives you four degrees of freedom to try to balance the equation (the fifth is just an overall scaling of the reaction). There is no solution to that problem here. It's like trying to solve "x=5 and x=7". Find x such that both equations are satisfied. You can't.