An aqueous solution of sodium hydroxide is standardized by titration with a 0.170 M solution of perchloric acid. If 28.5 mL of base are required to neutralize 16.0 mL of the acid, what is the molarity of the sodium hydroxide solution?

What happens to isotopes that are unstable?

What shape would a molecule with two bound groups and two lone pairs have?

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.)