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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.)

Each step in the following process has a yield of 70% ch4 + 4cl2 yield ccl4 +4hcl ccl4 + 2hf yield ccl2f2 + 2hcl of 4.50 mole ch4 reacts what is the total amount of hcl produced

Write balanced nuclear equations for the formation of five elements whose atomic number is between helium (2) and iron (26):