Final answer:
The carbides of lithium, sodium, potassium, calcium, and barium react with water to produce hydrogen gas and the respective metal hydroxide, not a single hazardous compound.
Step-by-step explanation:
The carbides of lithium, sodium, potassium, calcium, and barium react with water to produce hydrogen gas and the respective metal hydroxide, not a hazardous gas like hydrogen cyanide or acetylene.
For example, calcium carbide reacts with water to form acetylene gas and calcium hydroxide, but this is not the general case for the other carbides in question.
For alkali metals (group 1 elements such as lithium, sodium, potassium) and for alkaline earth metals like calcium and barium (group 2, except for beryllium and magnesium), the general reaction with water is:
Metal carbide + Water → Metal hydroxide + Hydrogen gas
Therefore, the correct answer to the question is that these carbides react with water to form hydrogen gas, which is flammable but not necessarily hazardous when properly managed. However, the question itself seems to imply the formation of a specific hazardous compound, which is not the case for these reactions with water.