Regular EL 4 Chemical Reactions Review

Front

What is the balanced equation for the reaction of magnesium with hydrochloric acid?

Back

Mg + 2 HCl -> MgCl2 + H2

Front

What is an exothermic reaction?

Back

An exothermic reaction is a chemical reaction that releases heat.

Front

Give an example of an exothermic reaction.

Back

Fire is an example of an exothermic reaction.

Front

What happens to water when left in an evaporating dish under the sun?

Back

It undergoes a physical change as it evaporates.

Front

What are coefficients in a chemical equation?

Back

Coefficients are the larger numbers in a chemical equation that can be changed to balance the equation.

Front

How do you determine the number of HCl molecules needed to balance a chemical equation?

Back

By using stoichiometry to ensure the number of atoms of each element is equal on both sides of the equation.

Front

What is the difference between a physical change and a chemical change?

Back

A physical change alters the form of a substance but not its chemical composition, while a chemical change results in the formation of new substances.

Front

What is the significance of balancing chemical equations?

Back

Balancing chemical equations ensures the law of conservation of mass is upheld, meaning the number of atoms remains constant.

Front

What is the role of heat in an endothermic reaction?

Back

In an endothermic reaction, heat is absorbed from the surroundings.

Front

What is the formula for hydrochloric acid?

Back

The formula for hydrochloric acid is HCl.