Hello, I have a question about something we learned in chemistry today.

We've been going over Ka/Kb table values, and using them to determine if a solution is acidic, basic or neutral.

One of the compounds (in aqueous solution) are NH4OCl (aq), which is supposedly basic. Can someone explain why that is?

For the salt of a weak acid and a weak base, (H^+) = sqrt(KwKa/Kb). For NH4OCl, that is about 4 x 10^-9 or pK about 8.4 (which is slightly basic). What it boils down to, if you look at the equation, is the Kw part will give neutral. If Ka = Kb, the solution is neutral. If Ka>Kb the solution is acid, if Ka<Kb, the solution is basic.

NH4OCl is a salt formed by the reaction between a weak base (NH3) and a strong acid (HCl). When NH4OCl is dissolved in water, it dissociates into NH4+ and OCl- ions. The NH4+ ion is derived from the weak base ammonia (NH3), while the OCl- ion is derived from the strong acid hydrochloric acid (HCl).

To determine whether NH4OCl is acidic, basic, or neutral, we need to consider the behavior of these ions in water.

The NH4+ ion can accept a proton from water to form NH3 and H3O+. This makes it behave as a weak acid.

On the other hand, the OCl- ion, being the conjugate base of a strong acid (HCl), does not react with water to a significant extent. It remains as a spectator ion.

Therefore, since NH4OCl produces higher concentrations of H3O+ ions than OH- ions, NH4OCl is considered to be acidic.

However, it is important to note that NH4OCl is not as acidic as strong acids like HCl or H2SO4. It is a weak acid due to the weak acid/base nature of the NH4+ ion derived from the weak base ammonia.

So, in summary, NH4OCl is considered acidic because it produces a higher concentration of H3O+ ions when dissolved in water.

Of course! I'd be happy to explain why NH4OCl is considered a basic compound in aqueous solution.

First, let's start with a brief overview of the concept of acidity and basicity. Acidity and basicity are related to the concentration of hydrogen ions (H+) and hydroxide ions (OH-) in a solution. An acidic solution has a higher concentration of H+ ions, while a basic solution has a higher concentration of OH- ions.

Now, to determine whether a substance is acidic, basic, or neutral, we can use the Ka or Kb values. Ka is the acid dissociation constant, which indicates the strength of an acid, while Kb is the base dissociation constant, which indicates the strength of a base.

In the case of NH4OCl, we can break down the equation into two parts:

NH4+ (aq) + H2O (l) ⇌ NH3 (aq) + H3O+ (aq)
NH4OCl (aq) + H2O (l) ⇌ NH4+ (aq) + Cl- (aq)

In the first equation, NH4+ acts as an acid and donates a proton (H+) to water, forming the weak base NH3 and the hydronium ion (H3O+). This is an example of the ammonium ion (NH4+) acting as a weak acid.

In the second equation, NH4OCl dissociates in solution to form NH4+ and Cl-. However, NH4+ can accept a proton (H+) from water, making it a weak base. As a result, NH4OCl can be considered a basic compound in aqueous solution.

To determine the degree of basicity, we can look at the Kb value for NH4+. The higher the Kb value, the stronger the base. Typically, the Kb value for NH4+ is relatively small, indicating that it is a weaker base compared to other substances.

In summary, NH4OCl is considered a basic compound in aqueous solution because NH4+ can accept a proton from water, making it a weak base.