Question #f2548 Chemistry The Mole Concept Percent Composition 1 Answer anor277 Oct 8, 2016 Approx. #16%# with respect to the starting mass of potassium nitrate. Explanation: We assume that (under fierce heating), #"potassium nitrate"# decomposes to give stoichiometric #"potassium nitrite"# and #"dioxygen gas"#: #KNO_3(s) + Delta rarr KNO_2(s) + 1/2O_2(g)uarr# And thus #1# #mol# of #"potassium nitrate"# loses #16*g# of oxygen gas upon decomposition. With respect to #KNO_3#, this represents a mass loss of: #(16*g)/(101.17*g)xx100%# #~=# #16%# Answer link Related questions What is mole percent? Question #e2e8b Question #bc737 Question #bc73b Question #e2e8f Question #b9857 Question #b985b Question #fee41 Question #c5c01 Question #bc73f See all questions in Percent Composition Impact of this question 1501 views around the world You can reuse this answer Creative Commons License