The unheated gas in the above system has a volume of 20.0L at a temperature of 25.0 °C and a pressure of 1.00 atm. The
gas is heated to a temperature of 100.0 °C while the volume
remains constant. What is the pressure of the heated gas?
Ignore the block labeled "A".
da Hint?

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)