Answer:
a)
⇒
⇒
b)
⇒
⇒
Explanation:
A)
Remember that positive number superscripts mean electrons lack and negative numbers mean electrons 'excess' (if we compare it with the neutral element). So, for the case of Fe2+ which is converted to Fe3+, we know that in Fe2+ there is a two electrons lack, while in Fe3+ there is a 3 electrons lack; it means that Fe2+ was converted to Fe3+ but releasing one electron:
⇒
The same analysis is applied to Br2; Br2 is a molecule which is said to have a zero superscript because it is an apolar covalent bond; and it is converted to Br-, which, according to what I wrote above, means that there is a one electron excess. So, Br2 must have received an electron in order to change to Br-; but Br2 can't change to Br- as simple as that because Br2 is a molecule, not an atom; it is a molecule that has two Br atoms, so, Br2 must give two Br- ions as products, but receiving one electron for each one:
⇒
b)
Applying the same, in Mg2+ there is a 2 electrons lack, and in Mg is not electron lack (its superscript is zero), so Mg must have released two electrons in order to change to Mg2+:
⇒
Cr3+ has a 3 electrons lack, and Cr2+ a two electrons one, so, Cr3+ must receive an electron to convert to Cr2+:
⇒
The answer is Independent Variable
Answer:
(70 x 2 + 16 x 3) x 29/70 x 2 = 38,9428571 g.
Explanation:
Answer:

Explanation:
The half-cell reduction potentials are
Ag⁺(aq) + e⁻ ⇌ Ag(s) E° = 0.7996 V
Fe²⁺(aq) + 2e⁻ ⇌ Fe(s) E° = -0.447 V
To create a spontaneous voltaic cell, we reverse the half-reaction with the more negative half-cell potential.
The anode is the electrode at which oxidation occurs.
The equation for the oxidation half-reaction is

Protons .because electron has negative charge and proton has positive charge.