Commonly Used Gases in the Laboratory Are Generally Obtained from Pressurized

Short Answer

Commonly used gases in the laboratory 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 as needed.For example, nitrogen monoxide, NO(g), can be prepared in the lab by the following chemical reaction:
3Cu(s)+ 8HNO₃(aq) $\rarr$ 2NO(g)+ 3Cu(NO₃)₂(aq)+ 4H₂O(l)
If 15 g of copper metal was added to an aqueous solution containing 6.0 moles of HNO₃, how many moles of NO(g)would be produced, assuming a 75% yield.