Which methods will you properly identify ph with indicator paper? check all that apply. set a piece of ph paper in front of each solution before testing to keep organized. dip the ph paper into each test tube and lay it on the table to let it change color. use a transfer pipet to remove a few drops from the solution to drop onto the paper. wait a minute or so before reading color. use the same piece of indicator paper for each solution to conserve paper.

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.)