Question
Hydrogen fuel calls are a promising alternative to gasoline engines in part because they release water instead of carbon dioxide. In a hydrogen fuel cell, hydrogen gas (O_2) react to make water as shown below. Which of the following statement is a true statement about how this reaction occurs? 2H_2 (g) + O_2 (g) rightarrow 2 H_2 O (g) Two molecules of H_2 and a molecule of O_2 collide at one time. A molecule of H_2 and a molecule of O_2 collide. The reactants must undergo a change of state for this reaction to occur. An H-H bond must form. An O-H bond must break. Refer to the following figure, illustrating the action of a HF and F^- buffer, to answer the question(s) below. The sizes of the boxes are proportional to the concentration in solution. Which of the following chemical equations represents the reaction that occurs when OH^- is added to the HF F^- buffer? HF +^- OH F^- + H_2 O
Explanation / Answer
19.
A.two molecules of H2 and a molecule of O2 must collide at the same time
One O-O bond and two H-H bonds broken.
4 O-H bonds are formed.
