Chemical Reactions

What is a chemical reaction?

A chemical reaction is a process where at least one new substance is formed through chemical change.

What are reactants?

Reactants are substances that enter a chemical reaction.

What are products?

Products are substances that are produced from a chemical reaction.

What are the five primary signs of chemical reactions?

1. Change in color 2. Change in odor 3. Production of new gases or vapors 4. Input or release of energy 5. Difficulty in reversing the process.

How is a chemical equation formatted?

A chemical equation has reactants on the left and products on the right.

Give an example of a chemical equation.

Magnesium oxide (MgO) reacts with carbon to produce carbon monoxide (CO) and magnesium (Mg).

What is required for a chemical equation to be valid?

It must represent known facts, contain correct reactant and product formulas, and satisfy the law of conservation of mass.

What do reactants and products represent in a chemical equation?

Reactants are the initial substances, while products are the substances formed after the reaction.

What is a word equation in chemistry?

A word equation connects the names of reactants and products in a chemical reaction.

Provide an example of a word equation.

Methane (CH4) reacts with oxygen (O2) to produce carbon dioxide (CO2) and water (H2O).

What is the importance of balancing chemical equations?

Balancing reflects the conservation of mass, ensuring that the number of atoms remains constant.

How do you balance the equation H2 + Cl2 → HCl?

The balanced equation is H2 + Cl2 → 2 HCl.

What do you do to visualize chemical reactions?

Use a visual representation that highlights reactants and products with appropriate coefficients.

What are the steps to balance a chemical equation?

1. Write a word equation. 2. Write correct formulas. 3. Adjust coefficients for balance.

Provide an example of a balanced equation.

For the reaction 2 Na + 2 H2O → 2 NaOH + H2.

What is the purpose of counting atoms in a reaction?

To confirm the number of each type of atom before and after the reaction.

What are the three phases described in chemical equations?

1. Solid (s): Rigid with definite volume and shape. 2. Liquid (l): Definite volume, shape can change. 3. Gas (g): No definite volume or shape.

What is a synthesis reaction?

A synthesis reaction is where two or more reactants combine to form one product, represented as A + B → AB.

Provide an example of a decomposition reaction.

2 H2O → 2 H2 + O2 is an example of a decomposition reaction.

What occurs in a double displacement reaction?

In a double displacement reaction, the anions and cations of two different compounds exchange places to form two new compounds.