Calculate the number of moles present in 9.52 x 10^24 molecules of hydrogen

Why is the vapor pressure of a warm lake higher than the vapor pressure of a cold lake? o a. warm water has a greater heat of vaporization. ob. warm water evaporates more quickly. cool water evaporates more quickly. od. cool water has a greater heat of vaporization.

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.)

Which of the following represents the ester functional group? a. -coo- b. -cho c. -cooh d. c=o