How many moles of P2O5 are formed by the complete combustion of 3.45 g of P4

Answer 1

Hi Lauren K.,

Write the balanced equation for the combustion. Note that the P may be represented just as that, you don't need to write it as P4! Then calculate the given P as moles, then ratio it through the equation.

OK, now that you've done that: what is P2O5 used for? It has one thing it excels at: establishing an anhydrous condition around it. But, it gets rapidly inactivated when it does that: it forms a syrupy gooey layer of H3PO4 on the surface, which is so viscous that further H2O transport through is prevented. Ironic, isn't it: the strongest easily generated desiccating agent "poops out" easily? P.S.: never fear, there are other desiccating agents that last better.

-- Cheers, --Mr. d.