Polysaccharides always:a. are a string of 3 or more sugar molecules. b. contain lipids. c. are polymers. d. The first and second choices are correct. e. The first and third choices are correct.

What is the total reduction potential of a cell in which potassium (k) is reduced and copper (cu) is oxidized? a. 2.59 v b. 3.27 v c. -3.27 v d.-2.59 v

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.)

Are oil and water a mixture or solution