Chlorine gas can be produced in the laboratory by the reaction indicated below. a 19.94g sample that is 92% k2cr2o7 is allowed to react with 50g of gaseous hydrogen chloride how much cl2 is produced in grams? K2Cr2O7+14HCl= 7H2O+2KCl+2CrCl3+3Cl2

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.)