Question

If a lab group were using hydrochloric acid to perform a substitution reaction, which precaution would not be a concern?

Answer 1

Answer:

A Flammability

Explanation:

A Flammability

B Health

C Reactivity

D Contact

Hydrochloric acid will not burn under normal fire conditions.

A substitution reaction is one in which an element or atom in a compound is displaced or substituted by another atom in the course of the reaction.

Hydrochloric acid is a strong and highly reactive acid that has the ability to burn solid substances that come in contact with it. Hence, it posses a health risk when the fumes are inhaled or when it gets in contact with the skin.

Hydrochloric acid is highly reactive and considered as a strong oxidizing agent. It has the capacity to react with several metals to liberate hydrogen gas, reacts with carbonate compounds to liberate carbon dioxide gas, etc.

However, hydrochloric acid is not flammable and therefore, will not burn under normal fire conditions.

The correct option is A.

Answer 2

The question is incomplete. Complete question is attached below:
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Correct Answer: Option A i.e Flammability

Reason:

Hydrochloric acid is a strong acid. It has a high value of dissociation constant. Following equilibrium is established with HCl is dissolved in water

           HCl     +       H2O           ↔          Cl-     +         H3O+

Above, reaction is highly exothermic in nature. So care must be taken while preparing HCl solution of desired concentration. HCl must be added in beaker containing water. Reversed, i.e. adding water in HCl, must never be done. This is because when acid is poured into water, it flows down the flask and mixes much efficiently and no boiling occurs. On other hand,  when water is added to acid, the very first drop of water will react with acid. The heat generated during this event might be high enough to boil the water instantly, which could spray acid out of the container.

The physical contact with concentration HCl will result in skin burn. As well, inhaling HCl vapors can cause burns to body tissues, lung damage and even death in extreme cases. Also, since HCl is a strong acid, it would undergoes reaction almost spontaneously, which would inturn favour substitution reaction. However, HCl is not a flammable gas. Hence, it is of no concern while performing substitution reaction.