Final answer:
The pKa of the conjugate acid of n-butyllithium would be extremely high due to n-butyllithium being a strong base. The exact value generally requires empirical data, but the pKa can theoretically be found using pKa = pkw - pKb equation, assuming pkw is 14.00 at 25°C.
Step-by-step explanation:
The student asked what is the pKa of the conjugate acid of n-butyllithium. In general, to find the pKa of a conjugate acid given the pKb of the base, we can use the formula pKa = pkw - pKb, where pkw is the ion-product constant of water, typically 14.00 at 25°C.
Because n-butyllithium is a strong base, its conjugate acid is extremely weak and therefore has a very high pKa. However, specific pKa values will require reference to empirical data or more complex calculations beyond simple arithmetic involving pkw. For typical weak bases such as dimethylamine, we can calculate:
pKa = pkw - pKb = 14.0 - (the value of pKb for dimethylamine) = 14.0 - 5.0 = 9.0.
This method demonstrates that the ionization constant for the ionization of the conjugate acid of a weak base is much lower than that for the base itself. For a strong base like n-butyllithium, the conjugate acid is so weak that its pKa is not typically listed, as it would be exceedingly high and the acid would hardly donate protons.