: If a 250. mL sample of the above buffer solution initially has 0.0800 mol H2C6H5O7 - and 0.0600 mol HC6H5O7 2- , what would be the new concentration of HC6H5O7 2- after 25.0 mL of 0.125 M NaOH is added to the buffer?

New concentration of is 0.23 M.

Explanation:

The given data is as follows.

     Moles of = 0.06 mol

     Moles of = 0.08 mol

Therefore, moles of added are as follows.

    Moles of =

                          = 0.003125 mol

Now, new moles of = 0.06 + 0.003125

                     = 0.063125

Therefore, new concentration of will be calculated as follows.

       Concentration =

                               = 0.23 M

Thus, we can conclude that new concentration of is 0.23 M.

the answer for sodium is 0.186

the answer for rubidium is 0.251