Chemical Reactions

Front

What is a coefficient in a chemical equation?

Back

The large number to the left of a formula that indicates how many molecules of that substance are involved in the reaction.

Front

How do you balance a chemical equation?

Back

By adjusting the coefficients in front of the reactants and products to ensure the same number of each type of atom on both sides of the equation.

Front

What happens to energy during an endothermic reaction?

Back

Energy is absorbed from the surroundings.

Front

What are indicators of a chemical change?

Back

Indicators include temperature change, color change, gas production (bubbling/fizzing), and the formation of a precipitate.

Front

What is the balanced equation for the reaction of aluminum and hydrochloric acid?

Back

2Al + 6HCl → 2AlCl3 + 3H2.

Front

What is an exothermic reaction?

Back

A chemical reaction that releases energy, usually in the form of heat.

Front

What is the law of conservation of mass?

Back

In a chemical reaction, mass is neither created nor destroyed; the total mass of reactants equals the total mass of products.

Front

What is a reactant?

Back

A substance that undergoes a chemical change in a reaction.

Front

What is a product in a chemical reaction?

Back

A substance that is formed as a result of a chemical reaction.

Front

What does it mean to say a reaction is 'balanced'?

Back

It means that the number of atoms for each element is the same on both sides of the equation.