Chemistry Chapter on Chemical Reactions

What evidence can indicate that a chemical reaction has occurred?

What is the main difference between a word equation and a skeleton equation?

Which process is an example of a physical change rather than a chemical change?

In a balanced chemical equation, what does the coefficient represent?

Which of the following equations uses chemical formulas to convey information about reactants and products?

What do gas bubbles produced during a reaction typically indicate?

Which step must be taken after adjusting coefficients in a chemical equation?

What is one reason why chemical equations must be balanced?

What occurs to particles during a chemical change?

Which characteristic best describes substances in a solid state?

Which factor does NOT influence Brownian motion?

How is a molecular formula different from an empirical formula?

Which of the following is a sign of a chemical reaction?

What is Brownian motion primarily the result of?

Which of the following statements is true regarding reactants and products?

What effect does increasing temperature have on Brownian motion?

Evidence of a Chemical Reaction

Temperature change can indicate a chemical reaction.
Many reactions release energy as heat and light.
Other reactions absorb heat.
Color change can indicate a chemical reaction.
Odor, gas bubbles, and the formation of a solid are also indicators of chemical change.

Representing Chemical Reactions

Equations are used to represent chemical reactions.
They show the reactants (starting substances) and products (substances formed).

Word Equations

Express reactants and products in words.
They lack information about the number of atoms involved.

Skeleton Equations

Show symbols and formulas for reactants and products.
They also lack information about the number of atoms involved.

Chemical Equations

Use chemical formulas to show the identities and relative amounts of the substances involved in a chemical reaction.

Balancing Chemical Equations

A coefficient is the number written in front of a reactant or product.
Balancing ensures the Law of Conservation of Mass is obeyed.

Steps for Balancing Equations

Write the skeleton equation for the reaction.
Count the atoms of each element in the reactants.
Count the atoms of each element in the products.
Change the coefficients to make the number of each element equal on both sides of the equation. This shows that atoms are conserved.
Write the coefficients in their lowest possible ratio.
Check your work.

Chemical Reactions

The process by which the atoms of one or more substances are rearranged to form different substances is called a chemical reaction.
Another name for a chemical reaction is a chemical change.

This quiz covers key concepts related to evidence and representation of chemical reactions. It discusses indicators of chemical changes, including temperature and color changes, and explains different types of equations used to represent these reactions. Test your understanding of balancing chemical equations and terminology.