Zinc reacts with excess hydrochloric acid to produce zinc chloride and hydrogen gas. what happens to the reaction rate if you increase the concentration of zinc?

a. the reaction rate decreases because the area available for particle movement is decreased.
b. the reaction rate decreases because the probability the reverse reaction is more likely.
c. the reaction rate increases because the energy of each particle increases.
d. the reaction rate increases because the probability of collisions increases.

Dying the folding patterns of protein molecules can microbiologists better understand cellular processes as well as some diseases, such as alzheimer’s, that are caused by proteins that have misfolded. the folding of these complicated molecules can be simulated on computers, but it takes a lot of processor power and time for even expensive supercomputers to do this. a group of researchers at stanford university developed software that can be used to distribute the processing of data to anyone who is willing to donate time on their idle personal computers. as a result, the researchers have been able to achieve protein-folding simulations that are far better than those other computing methods have done. which statement best describes the work of these researchers? the work is not scientific because the data are not processed in one location. the work is not scientific because the simulations are not reproducible. the researchers applied creativity to solve a problem in running an experiment. the researchers used only well-established scientific techniques.

2points why do scientists need governmental funding? o a. government politicians ask all the important scientific questions. o b. scientists have to pay taxes to the government on the money they make. o c. the cost of doing scientific research can be very high. o d. the government is controlled by scientists. submit

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.)