Answer: The answers are the first and third options.
Answer:
pH = 10.9
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to say that the undergoing reaction between this buffer and OH⁻ promotes the formation of more CO₃²⁻ because it acts as the base, we can do the following:

The resulting concentrations are:
![[CO_3^{2-}]=\frac{0.1435mol}{0.25L}=0.574M \\](https://tex.z-dn.net/?f=%5BCO_3%5E%7B2-%7D%5D%3D%5Cfrac%7B0.1435mol%7D%7B0.25L%7D%3D0.574M%20%5C%5C)
![[HCO_3^{-}]=\frac{0.0265mol}{0.25L}=0.106M](https://tex.z-dn.net/?f=%5BHCO_3%5E%7B-%7D%5D%3D%5Cfrac%7B0.0265mol%7D%7B0.25L%7D%3D0.106M)
Thus, since the pKa of this buffer system is 10.2, the change in the pH would be:

Which makes sense since basic OH⁻ ions were added.
Regards!
D. hope this helps your question
The pairs are:
K, Kr - Same period
Be, Mg - Same group
Ni, Tc - Both are transition metals
B, Ge - Both are metaloids
Al, Pb - Both form inert oxides