One of these reactions represents the laboratory preparation of hydrogen.
One of these reactions represents the laboratory preparation of hydrogen.
- A)C(s) + H\(_2\)O(l)\(\rightarrow\) CO(g) + H\(_2\)(g)
- B)2Na(s) + 2H\(_2\)0(1) \(\rightarrow\) 2NaOH(aq) + H\(_2\)(g)
- C)Cu(s) + H\(_2\)O(l) \(\rightarrow\) CuO(s) + H\(_2\)(g)
- D)Zn(s) + 2HCl(aq) \(\rightarrow\) ZnCl\(_2\)(aq) + H\(_2\)(g)
Correct Answer: D)Zn(s) + 2HCl(aq) \(\rightarrow\) ZnCl\(_2\)(aq) + H\(_2\)(g)
Explanation
Hydrogen gas can be prepared in the laboratory through a variety of chemical reactions. The correct answer in this case isOption E, which represents the reaction between zinc (Zn) and hydrochloric acid (HCl):
\(Zn(s) + 2HCl(aq) \rightarrow ZnCl_2(aq) + H_2(g)\)
This reaction is an example of a single displacement reaction, where a more reactive metal (such as zinc) displaces a less reactive metal (hydrogen in this case) from its compound (HCl). As a result, hydrogen gas is produced and released, while the zinc forms a new compound with the chloride ions.
It's important to note that there are other methods to produce hydrogen gas in the laboratory, such as the reaction between a metal and water (Option B), but this example is not the most commonly used method due to the highly reactive nature of sodium metal. The other options do not form hydrogen gas as a product, making them incorrect for this specific question.