Common Gases Used in Laboratories Are Generally Obtained from Pressurized $\rarr$

Short Answer

Common gases used in laboratories are generally obtained from pressurized metal gas cylinders, but for small amounts of occasionally-used gases, it is sometimes easier just to prepare them chemically.For example, oxygen gas can be prepared by heating KMnO₄(s)according to the following chemical reaction:
2KMnO₄(s) $\rarr$ K₂MnO₄(s)+ MnO₂(s)+ O₂(g)
The above procedure was carried out starting with 93.2 g of KMnO₄, and it was later determined that all of the KMnO₄ reacted according to the above equation except 11.7 g.What was the percent yield for the reaction?