How many moles of electrons are required to discharge 1 mole of the following ions: Mg^2+, K^1+, Al^3+, O^2-.

Expert Answers

An illustration of the letter 'A' in a speech bubbles

To solve this, first write an equation showing what is happening to each of the elements. Then look at the coefficients to determine the moles of electrons per mole of ion.

Mg = Mg^+2 + 2 e^-1  this means that when magnesium is oxidized it loses two moles of electrons for every mole of magnesium you started with.

K = K^+1 + 1 e^-1  or one mole of electrons produced per mole of potassium ion formed

Al = Al^+3 + 3 e^-1  or three moles of electrons produced per mole of aluminum ion formed

O + 2 e^-1 = O^-2   It takes two moles of electrons to form one mole of oxygen ion.

See eNotes Ad-Free

Start your 48-hour free trial to get access to more than 30,000 additional guides and more than 350,000 Homework Help questions answered by our experts.

Get 48 Hours Free Access
Approved by eNotes Editorial