Ascientist is at the hospital visiting a friend's young daughter, who has been
diagnosed with a respiratory virus. on his way out, he speaks with a nurse
and discovers that the pediatric wing of the hospital was recently converted
into a respiratory disease unit due to the recent rise in respiratory infection,
the scientist realizes that respiratory disease is a serious problem. the
scientist is in which part of the engineering process?

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.)