PART C
Directions
Each of the incomplete statements or questions below is followed by five suggested
completions or answers. Select the one that is best for each case.
25 . What is the percentage by mass of sulfur in H 2 SO 4?
(A) 16%
(B) 33%
(C) 36%
(D) 42%
(E) Cannot be determined
26 . BaCl 2 dissociates in water to give one Ba2+ ion and two Cl– ions. If concentrated HCl is
added to this solution:
(A) [Ba2+] increases
(B) [Ba2+] remains constant
(C) [OH–] increases
(D) the number of moles of undissociated BaCl 2 increases
(E) [H+] decreases
27 . What is the percent composition by weight of Al in Al 2 (SO 4 ) 3?
(A) 7.9%
(B) 31.6%
(C) 15.8%
(D) 12.7%
(E) 22.3%
