Ved: Chapter

Chapter List

CH5.3

Problem

Problem List

10SMB

Printed circuit boards are used in the electronics industry to both connect and hold components in place. In production, 0.03 in. of copper foil is laminated to an insulating plastic board. A circuit pattern made of a chemically resistant polymer is then printed on the board. Next, the unwanted copper is chemically etched away by using selected reagents. If copper is treated with Cu(NH3 ) 4Cl2 (cupric ammonium chloride) and NH4OH (ammonium hydroxide), the products are water and Cu(NH3) 4Cl (cuprous ammonium chloride). Once the copper is dissolved, the polymer is removed by solvents, leaving the printed circuit ready for further processing. If a single-sided board 4 in. by 8 in. is to have 75% of the copper layer removed using these reagents, how many grams of each reagent will be consumed? Data: The density of copper is 8.96 g/cm3.​