Law of Conservation of Mass

Front

What is the Law of Conservation of Mass?

Back

The Law of Conservation of Mass states that in a closed system, the total mass of reactants before a chemical reaction is equal to the total mass of products after the reaction.

Front

If a reaction starts with 20g of reactants, how much mass should the products have?

Back

20g of products.

Front

What does it mean for a chemical reaction to be balanced?

Back

A chemical reaction is balanced when both sides have the same number of atoms for each element.

Front

What is a coefficient in a chemical equation?

Back

A coefficient is the number placed in front of a compound or element in a chemical equation that indicates how many molecules or moles are involved.

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What is a subscript in a chemical formula?

Back

A subscript is a number written below and to the right of a chemical symbol that indicates the number of atoms of that element in a molecule.

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How can you tell if a chemical equation is balanced?

Back

You can tell if a chemical equation is balanced by counting the number of atoms of each element on both sides of the equation and ensuring they are equal.

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What is the significance of balancing chemical equations?

Back

Balancing chemical equations is important because it reflects the conservation of mass and ensures that the same amount of each element is present before and after the reaction.

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What happens to mass during a chemical reaction?

Back

The mass is neither created nor destroyed during a chemical reaction; it is conserved.

Front

What is an example of a balanced chemical equation?

Back

2H2 + O2 -> 2H2O is a balanced equation, as there are 4 hydrogen atoms and 2 oxygen atoms on both sides.

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What is an unbalanced chemical equation?

Back

An unbalanced chemical equation is one where the number of atoms of each element is not the same on both sides of the equation.