2 HCl (aq) + Zn(s)----> H2 (g) + Zn2+(aq) + 2 Cl-(aq)
Once the iron was free of the zinc layer, it was then weighed again for its new mass. The mass remaining is the mass of the iron present that was underneath the zinc layer.
To calculate the mass of the zinc coating: mass before treatment – mass after treatment. It was possible to find the thickness of the zinc layer on each side of the iron by using the formula:
Volume = length x width x thickness
Knowing the mass of the iron and the zinc, It was possible to convert grams to moles using the following equation:
(mass present g) x (1 mol) = mol …show more content…
The purpose is to protect the metal from corrosion or rusting. The zinc layer has a much higher corrosion potential and sacrificially corrodes to keep the iron from corroding instead. In the experiment, 10ml of hydrochloric acid was obtained and added to a graduated cylinder. The galvanized iron was then placed inside the acid. A chemical change was taking place by the metal being in the hydrochloric acid. This was obvious by two ways. The first being that the original, galvanized piece of sheet metal was shiny before being put in. After being placed in the acid, the metal was much less shiny and weighed less. The acid was eating away at the zinc coating on the surface of the metal causing the solution to bubble vigorously, indicating that a gas (hydrogen) was being released. This was the corrosion taking