Aspirin (acetylsalicylic acid, c9h8o4) is a weak monoprotic acid. to determine its acid-dissociation constant, a student dissolved 2.00 g of aspirin in 0.600 l of water and measured the ph. what was the ka value calculated by the student if theph of the solution was 2.62? a 0.100 m solution of ethylamine (c2h5nh2) has a ph of 11.87. calculate the kb for ethylamine.

Explanation:

We have to start with the calculation of the concentration of the acid, using the molar mass:

Molas mass of = 180.16 g/mol

The,  with the ionization equation for aspirin, using the ICE table, we can calculate the Ka expression.

            HA     <=>    A^-      +      H^+

I       0.019             Zero            Zero

C           -X               +X               +X

E     0.019-X              X                  X

Now, we can calculate X using the pH value:

With this value we can calculate the Ka, so:

.

For the ethylamine we have to follow the same procedure:

         B^-    +    H2O     <=>    BH      +      OH^-

I          0.1              /                  Zero            Zero

C           -X            /                   +X               +X

E          0.1-X          /                    X                  X

Now, we can calculate X using the pH value:

With this value we can calculate the Kb, so:

in chemistry, a solution’s concentration is how much of a dissolvable substance, known as a solute, is mixed with another substance, called the solvent. the standard formula is c = m/v, where c is the concentration, m is the mass of the solute dissolved, and v is the total volume