Question

From the activity list included in this problem, which element/ion is the most difficult to reduce?

Activity Series = Li(s)→K(s)→Ca(s)→Na(s)→Li+(aq)+K+(aq)+Ca2+(aq)+Na+(aq)+e−e−2e−e−


Na

Li+

Li

Na+

C

Answer 1

Li+ (lithium ion) is the most difficult to reduce based on the activity series because it is at the top of the list, indicating a higher ionization energy due to its positive charge.

Step-by-step explanation:

From the given activity list, which reflects the ease of oxidation of the elements and their ions, Li+ (lithium ion) is the most difficult to reduce.

The activity series suggests that the metals are listed in order of decreasing reactivity, meaning elements towards the top are more easily oxidized (lose electrons) and their ions are more difficult to reduce (gain electrons).

Thus, lithium ion (Li+) being closest to the top of the list of ions, would be the most difficult to reduce back to its metallic form, which corresponds to having a higher ionization energy (IE) than lithium metal (Li). This is because removing an additional electron from Li+ would require even more energy as it is already positively charged.