Question

Which of the following has the strongest conjugate base?

a) acetic acid, Ka = 1.8 x 10⁻⁵
b) HNO₂, Ka = 4.5 x 10⁻⁴
c) HPO₄²⁻, Ka = 4.8 x 10⁻¹³
d) Vitamin C, Ka = 8.0 x 10⁻⁵

Answer 1

The strongest conjugate base among the given options is the conjugate base of HPO₄²⁻, as it has the smallest Ka value (4.8 x 10⁻¹³), indicating it is the weakest acid and therefore has the strongest conjugate baseC) HPO42-,Ka=4.8 10-13.

Step-by-step explanation:

The student has asked which of the following has the strongest conjugate base: a) acetic acid, Ka = 1.8 x 10⁻⁵; b) HNO₂, Ka = 4.5 x 10⁻⁴; c) HPO₄²⁻, Ka = 4.8 x 10⁻¹³; d) Vitamin C, Ka = 8.0 x 10⁻⁵. To determine which has the strongest conjugate base, we look for the compound with the weakest acid.

The acid strength is indicated by its Ka value: the smaller the Ka, the weaker the acid, and thus the stronger its conjugate base. Among the given options, HPO₄²⁻ has the smallest Ka value of 4.8 x 10⁻¹³, which indicates that it is the weakest acid and hence its conjugate base is the strongest.