When the cotton balls are placed in the ends of a tube at the same time, the gases diffuse from each end and meet somewhere in between, where they react to form a white solid. Which of the following combinations will produce a solid closest to the center of the tube?
(A) HCl and CH,NH
(B) HCI and NHs
(C) HBr and CHNH,
(D) HBr and NH
