The penny coin was removed from circulation in Canada
In February of 2014. The United States may soon do the
same. The major reason for this move was the rising value
of copper metal. When copper’s value increased, pennies
were produced as a zinc slug with a thin layer of copper
plated over top. Zinc reacts readily with hydrochloric acid,
while copper does not. A triangular file is used to nick the
edge of a penny to expose the zinc slug below the layer
of copper. The zinc reacts with the acid releasing bubbles
from the nicked area until nothing remains but a thin shell
of copper. If 0.948 L of hydrogen gas is collected over water
at 20.0°C and a total pressure of 752 mm Hg, determine the
percentage by mass of the copper in the 2.586 g penny.