J.R. S. answered 01/22/23
Ph.D. University Professor with 10+ years Tutoring Experience
Pr6O11 is one form of praseodymium oxide.
Pr6O11 + 18HNO3 + 27H2O ==> 6Pr(NO3)3·6H2O + O2
I think this is the properly balanced equation obtained by balancing individual redox half reactions.
According to this equation you would want to use 1 mole of P6O11 and 18 moles of HNO3.
1 mol P6O11 = 1021.44 g
18 moles HNO3: 18 moles x 63.01 g / mol = 1134 g HNO3
Since it is 68% (m/m) then 1134 g / 0.68 = 1668 g of the HNO3 solution
So, in summary, assuming the balanced equation is the correct one (I believe it is)...
React 1021 g of P6O11 with 1668 g of the 68% HNO3 in an aqueous medium, and you should produce 6Pr(NO3)3·6H2O