Equilibrium Expressions in Chemistry

The video tutorial revisits the concept of creating equilibrium expressions, focusing on the use of balanced chemical equations. It explains how to construct the equilibrium constant (KQ) by placing the concentrations of products over reactants, using coefficients as exponents, and excluding solids and liquids. The tutorial includes three examples: a gas phase reaction, a solid dissolving into aqueous products, and HCN dissolving in water. Each example demonstrates the application of these principles in calculating KQ.

What is the main purpose of this video?

• To discuss the history of chemistry

• To explain the periodic table

• To redo a previous video with better quality

• To introduce a new chemical concept

What is required to create an equilibrium expression?

• A balanced chemical equation

• A periodic table

• A list of elements

• A set of chemical reactions

In an equilibrium expression, where are the concentrations of products placed?

• Outside the fraction

• In the numerator

• In the denominator

• In a separate equation

Which states of matter are included in equilibrium expressions?

• All states of matter

• Solids and liquids

• Only gases

• Aqueous and gases

In the example with gases, what is the exponent for HCl?

• One

• Four

• Two

• Three

Why is NCl3 included in the equilibrium expression?

• It is an aqueous solution

• It is a solid

• It is a liquid

• It is a gas

In the example with a solid dissolving, what is the exponent for Ca2+?

• Four

• Two

• Three

• One

Why is there no denominator in the example with a solid dissolving?

• The reactant is a liquid

• The reactant is a solid

• The reactant is a gas

• The reactant is an aqueous solution

In the example with a liquid reactant, why is water not included in the equilibrium expression?

• It is a liquid

• It is a gas

• It is a solid

• It is an aqueous solution

What becomes the exponents in an equilibrium expression?

• The atomic numbers

• The coefficients from the balanced equation

• The number of moles

• The temperature values