1.2 Do 1: Keeping the Balance

Front

What is the law of conservation of mass?

Back

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction; the total mass of the reactants equals the total mass of the products.

Front

Why is mass conserved in a chemical reaction?

Back

Mass is conserved in a chemical reaction because the number of atoms remains constant; atoms are rearranged but not created or destroyed.

Front

What happens to the total mass when reactants are converted to products in a chemical reaction?

Back

The total mass remains the same; the mass of the reactants equals the mass of the products.

Front

How can you demonstrate the conservation of mass in a chemical reaction?

Back

You can demonstrate conservation of mass by weighing the reactants before the reaction and the products after the reaction; both weights should be equal.

Front

What is a chemical reaction?

Back

A chemical reaction is a process in which substances (reactants) are transformed into different substances (products) through the breaking and forming of chemical bonds.

Front

What are reactants in a chemical reaction?

Back

Reactants are the starting substances that undergo a chemical change during a reaction.

Front

What are products in a chemical reaction?

Back

Products are the substances that are formed as a result of a chemical reaction.

Front

Can mass be lost in a chemical reaction?

Back

No, mass cannot be lost in a chemical reaction; it is conserved.

Front

What is an example of a chemical reaction that demonstrates conservation of mass?

Back

An example is the combustion of methane (CH4) in oxygen (O2) to produce carbon dioxide (CO2) and water (H2O); the total mass of reactants equals the total mass of products.

Front

What role do coefficients play in a balanced chemical equation?

Back

Coefficients indicate the number of molecules or moles of each reactant and product involved in the reaction, ensuring mass balance.