Redox Reactions and Oxidation States

These flashcards cover key concepts, definitions, and reactions related to redox processes and oxidation states in chemistry.

Oxidation is defined as the __ of electrons.

Removal (loss) of electrons.

Reduction is defined as the __ of electrons.

Gain of electrons.

In the reaction 2Mg + O2 ——> 2MgO, magnesium is __ because it has gained oxygen.

oxidised

In the reaction CuO + H2 ——> Cu + H2O, copper(II) oxide is __ as it has lost oxygen.

reduced

The acronym 'OIL' stands for __, while 'RIG' stands for __.

Oxidation Is Loss; Reduction Is Gain

To calculate the oxidation state of an element, one must consider its __ in the periodic table.

position

In a compound, the oxidation states must add up to __.

the overall charge of the compound.

In the ion SO42-, the oxidation state of sulfur (S) is __.

+6

The oxidation state of oxygen is usually __, except in peroxides where it is __.

-2; -1

Metals typically have __ oxidation states in compounds, usually corresponding to their group number.

positive

In the compound MnO4¯, the oxidation state of manganese (Mn) is __.

+7

When balancing redox equations, if the charges on both sides do not match, you must add __ to one side.

sufficient H+ ions.

The sum of the oxidation states in CO2 equals __, demonstrating that it is a neutral molecule.

zero

In complex ions, the sum of oxidation states adds up to the __ of the ion.

charge

Electronegativity increases across a and decreases down a .

period; group

The oxidation state of hydrogen is normally __, except in hydride ions where it is __.

+1; -1

In the half-reaction Fe2+ → Fe3+, the process is a __ since it involves an increase in oxidation state.

oxidation

When forming redox equations, ensure to combine half equations so that the __ of electrons is the same in both.

number

Chlorine (Cl) can have positive oxidation states, such as +1, +3, +5, or +7, based on its __ in the periodic table.

group number

The oxidation state of elements in their natural state (like O2 or H2) is __.

0

The __ method is used to write out two half equations for a redox reaction, then combine them for the overall reaction.

two-step

Balancing the equation involving Cr2O72- and I¯ requires determining the __ needed to balance oxidation states.

electrons