CHE140 Introduction to Redox Reactions and Stoichiometry

Vocabulary and key concepts from the lecture on chemical reaction stoichiometry, ionic compounds, and redox reaction fundamentals.

Stoichiometry

The use of a reaction equation to work out how much of things we have, referring to the coefficient in front of a compound to measure chemicals or elements.

Theoretical Yield

The amount of product that can be produced from the limiting reagent.

Percentage Yield

The amount actually produced divided by the theoretical yield, multiplied by $100\%$.

Cation

An atom or molecule with a positive ($+$) charge.

Anion

An atom or molecule with a negative ($-$) charge.

Formula Unit

The smallest amount of ions (positive and negative) put together to achieve a total charge of zero.

Polyatomic Ion

A cation or anion made up of multiple elements, such as hydroxide ($OH^-$).

Redox Reactions

Reactions that involve the transfer of electrons, where one compound is oxidized and another is reduced.

Oxidation

The process where a species loses electrons ($\text{OIL}$: Oxidation Is Loss), causing the oxidation number to become more positive or less negative.

Reduction

The process where a species gains electrons ($\text{RIG}$: Reduction Is Gain), causing the oxidation number to become more negative or less positive.

Oxidation Number

A value used to track the movement of electrons; elements in their elemental form always have an oxidation state of zero.

Reducing Agent

The species in a redox reaction that is oxidized and causes another species to be reduced.

Oxidizing Agent

The species in a redox reaction that is reduced and causes another species to be oxidized.

Half Equation Method

A method of balancing redox reactions by looking at the reduction and oxidation processes separately, including balancing oxygen with $H_2O$ and hydrogen with $H^+$.

Hydride

A compound where hydrogen acts as the anion, such as sodium hydride, resulting in a different oxidation state for hydrogen than its usual $+1$.