Which of the following \( K_{b} \) values represents the weakest base? A. \( K_{b}=7.41 \times 10^{-5} \) B. \( K_{b}=1.26 \times 10^{-6} \) C. \( K_{b}=1.8 \times 10^{-5} \) D. \( K_{b}=3.8 \times 10^{-10} \)

To determine which \( K_{b} \) value represents the weakest base, we need to look for the smallest \( K_{b} \) value. The smaller the \( K_{b} \), the weaker the base, as it indicates a lesser propensity to ionize and accept protons from water. In this case, the options given are: A. \( K_{b}=7.41 \times 10^{-5} \) B. \( K_{b}=1.26 \times 10^{-6} \) C. \( K_{b}=1.8 \times 10^{-5} \) D. \( K_{b}=3.8 \times 10^{-10} \) The weakest base corresponds to \( K_{b}=3.8 \times 10^{-10} \) (Option D), as it is the lowest value among the choices, indicating that it is the least capable of accepting protons and thus is the weakest base.