Citric acid ( h 3 c 6 h 5 o 7 h3c6h5o7 ) has p k a pka values of 3.128 ( p k a1 pka1 ), 4.761 ( p k a2 pka2 ), and 6.396 ( p k a3 pka3 ).

a. what is the predominant form of citric acid at ph 4.23 4.23 ? hc 6 h 5 o 2 − 7 hc6h5o72− h 2 c 6 h 5 o − 7 h2c6h5o7− h 3 c 6 h 5 o 7 h3c6h5o7 c 6 h 5 o 3 − 7 c6h5o73−
b. what is the predominant form of citric acid at ph 6.05 6.05 ? h 3 c 6 h 5 o 7 h3c6h5o7 c 6 h 5 o 3 − 7 c6h5o73− h 2 c 6 h 5 o − 7 h2c6h5o7− hc 6 h 5 o 2 − 7 hc6h5o72−
c. what is the second most abundant species of citric acid at ph 4.23 4.23 ? c 6 h 5 o 3 − 7 c6h5o73− h 2 c 6 h 5 o − 7 h2c6h5o7− h 3 c 6 h 5 o 7 h3c6h5o7 hc 6 h 5 o 2 − 7 hc6h5o72−
d. what is the second most abundant species of citric acid at ph 6.05 6.05 ? c 6 h 5 o 3 − 7 c6h5o73− h 2 c 6 h 5 o − 7 h2c6h5o7− h 3 c 6 h 5 o 7 h3c6h5o7 hc 6 h 5 o 2 − 7

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.

a). in this case, dh> 0 and sd> 0. if t becomes larger, the term "-tds" will become more negative. at some point, it is possible that -dts will be more negative than the dh is positive, and the reaction will become spontaneous. this is probably the correct answer, but you should look at all of the other possibilities and make sure of that.