What was the substance used in air conditioners that was found to be environmentally unfriendly? What damage did they cause?

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 changes will decrease the total amount of gaseous solute able to be dissolved in a liter of liquid water? (2 points) decreasing temperature decreasing pressure decreasing surface area decreasing solute concentration

The goal of this experiment was to answer the question "what is the effect of a gas' temperature on its volume? " you formulated the hypothesis below. hypothesis: if a fixed amount of gas is heated, then the volume will increase because the heat will cause the molecules of gas to move faster and further apart. to test this hypothesis, you changed the of the gas between 0 and 100°c (273 and 373 k) and calculated the resulting of the gas.