The [H3O+] of a solution with pH = 3 is

-10 M.
10 M.
1 x 10-3 M.
1 x 103 M.
1 x 10-11 M.

Identify the acid(s) and base(s) in the following reaction:

CH3COOH(aq) + NH3(aq) CH 3COO-(aq) + NH4+(aq)

CH3COOH is the only acid, and NH3 is the only base.
CH3COOH is the only base, and NH3 is the only acid.
CH3COOH and NH4+ are acids, and NH3 and CH3COO- are bases.
CH3COOH and NH3 are acids, and NH4+ and CH3COO- are bases.

For 1, pH = -log(H^+). Plug and chug. If you don't understand how to do this, explain your exact problem and I can help you through it. (It may be so simple that you just don't know how to handle the calculator.).

#2. No arrow. I don't know the reactants from the products. But the answer is to apply the Bronsted-Lowry theory of acids/bases.
Remember,
HA + H2O ==> H3O^+ + A^-

So HA is an acid because it donates a proton (to H2O) to form A^- (the conjugate base of HA) while H2O is a base (it accepts a proton from HA) and it forms the conjugate acid(H3O^+).

To find the [H3O+] of a solution with pH = 3, we need to first understand the relationship between pH and [H3O+].

The pH scale is a measure of acidity or basicity of a solution and is defined as the negative logarithm (base 10) of the concentration of hydrogen ions ([H+]). Mathematically, it can be represented as:

pH = -log[H+]

To convert this equation to [H3O+] instead of [H+], we need to understand that in an aqueous solution, hydrogen ions (H+) are usually present in the form of hydronium ions (H3O+). Therefore, [H+] is approximately equal to [H3O+].

Once we have the pH value, we can calculate [H3O+] by taking the antilog of the negative pH value. In this case, pH = 3, so:

[H3O+] = 10^(-pH)

Plugging in the value:

[H3O+] = 10^(-3)

Simplifying this expression gives us:

[H3O+] = 1 x 10^(-3) M

Therefore, the answer is 1 x 10^(-3) M.

Moving on to the second question, we need to identify the acid(s) and base(s) in the given reaction:

CH3COOH(aq) + NH3(aq) → CH3COO-(aq) + NH4+(aq)

In this reaction, CH3COOH (acetic acid) donates a proton (H+) and acts as an acid, while NH3 (ammonia) accepts a proton and acts as a base. Therefore, CH3COOH is an acid, and NH3 is a base.

The products of the reaction, CH3COO- (acetate ion) and NH4+ (ammonium ion), are formed by the transfer of a proton. NH4+ accepts the proton, making it a conjugate acid, and CH3COO- donates the proton, making it a conjugate base.

Hence, the correct answer is: CH3COOH is the only acid, and NH3 is the only base.