What is the most significant change in the comet's energy as it moves from point D to point A? (Assume that total mechanical energy is conserved.) A. KE decreases, GPE decreases
B. KE increases, GPE increases
C. KE increases, GPE decreases
D. KE decreases, GPE increases

If a reactant was removed, did the new equilibrium system shift to make more reactants or more products?

Calculate - analysis of compound composed of iron and oxygen yields 174.86 of fe and 75.14g of o. what is the empirical formula for this compound?

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.)