The hydrolysis of pyrophosphate can be described by the reaction h2po2 7 +h2o ! 2h2po 4 if the ph is held constant, the reaction is pseudo-first order with respect to h2po2– 7 . 126 (a) if, at a given ph, the half-life of pyrophosphate is 140 h at 75c and 13 h at 100c, what is ear for the reaction? (b) estimate the time required for 50% hydrolysis of pyrophosphate in a solution at the same ph as in part (a), but at 20c.

Explanation:

Relation between half-life and rate constant is as follows.

       Half life

Hence, calculate the rate constant as follows.

               k =

                   = 0.00495

Hence, rate constant at is 0.00495 .

Now, at , value of rate constant will be as follows.

            k =

              = 0.0533

Hence, calculate the activation energy as follows.

            = 102.6 kJ/mol

Therefore, value of activation energy is  102.6 kJ/mol .

Now, k at ,

Calculate the time as follows.

           kt =

                   t = 108985 hours

Thus, we can conclude that time required for 50% hydrolysis of pyrophosphate is 108985 hours.

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.