27 . Which of the following statements about molecular and empirical formulas is (are) false?
I. A given compound can have the same molecular and empirical formula.
II. The molecular formula is a whole-number multiple of the empirical formula.
III. H 2 O 2 represents the empirical formula of hydrogen peroxide.
(A) III only
(B) I and II only
(C) II and III only
(D) I, II, and III
(E) I only
28 . The product formed when oxygen and hydrogen are mixed in a test tube at room
temperature is
(A) hydrogen peroxide
(B) water
(C) a base
(D) a zwitterion
(E) no reaction takes place
29 . All of the following statements are consistent with Bohr’s model of the atom EXCEPT
(A) an electron may assume an infinite number of velocities
(B) an atom is most stable when its electronic configuration is that of the ground state
(C) the electron shell numbers represent the principal energy levels
(D) electrons in orbitals closest to the nucleus have the lowest energy
(E) they are all consistent
30 . What is the amount of heat given off by 100 g of O 2 when it is used to burn an excess of
sulfur according to the following reaction?