A laboratory assistant was experimenting with chemical reactions when she combined a small amount of zinc (Zn) with hydrochloric acid (HCl). She discovered that zinc chloride (ZnCl2) [2 should be small and below the Cl] and hydrogen (H2) [2 should be small and below the H] were produced. Which of the following substances are the reactants? PLEASE PLEASE
A. Zn + HCl
B. ZnCl2 + H2
C. Zn + H2
D. ZnCl2 + HCl

Calculate the change in entropy if br2(l) is converted into gaseous br atoms. s° for br2(l) = 152.2 j/(mol•k) s° for br2(g) = 245.5 j/(mol•k) s° for br(g) = 175.0 j/(mol•k)

Hot air balloons float in the air because of the difference in density between cold and hot air. in this problem, you will estimate the minimum temperature the gas inside the balloon needs to be, for it to take off. to do this, use the following variables and make these assumptions: the combined weight of the pilot basket together with that of the balloon fabric and other equipment is w. the volume of the hot air inside the balloon when it is inflated is v. the absolute temperature of the hot air at the bottom of the balloon is th (where th> tc). the absolute temperature of the cold air outside the balloon is tc and its density is ďc. the balloon is open at the bottom, so that the pressure inside and outside the balloon is the same. as always, treat air as an ideal gas. use g for the magnitude of the acceleration due to gravity.

Match the acid base pairs by arranging the acid name with the conjugate base formula. hydrogen carbonate hydrogen phosphate carbonic acid read water sulfuric acid phosphoric acid a. co32- b. hso4- c. hco3- d. po43- e. h2po4- f. oh-