1. If your phone needs to be on a charger for three hours to be fully charged, and the charger draws 2 amps, then how many electrons have to flow?

Why do cells appear different in distilled water than they do in 10% salt water?

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.)

Calculate the molarity of each of the following solutions. part a) 0.12 mol of lino3 in 5.5 l of solution part b) 60.7 g c2h6o in 2.48 l of solution part c) 14.2 mg ki in 100 ml of solution