Law of Conservation of Matter

Front

What is the Law of Conservation of Matter?

Back

The Law of Conservation of Matter states that matter cannot be created or destroyed in a chemical reaction; it can only change forms.

Front

What is a coefficient in a chemical equation?

Back

A coefficient is a number placed in front of a chemical formula in an equation to indicate how many molecules or moles of that substance are involved in the reaction.

Front

Balance the following chemical reaction: _N2 + _H2 --> _NH3

Back

1, 3, 2

Front

How many atoms of aluminum are in the equation: 4Al + 3O2 --> 2Al2O3?

Back

4

Front

What does a subscript in a chemical formula indicate?

Back

A subscript indicates the number of atoms of the element in a molecule.

Front

Identify the subscripts in the chemical formula: 3Fe2O4.

Back

2, 4

Front

What happens to the mass of products in an open system during a chemical reaction?

Back

The measurable mass might decrease because any gas produced can escape.

Front

What is the difference between a coefficient and a subscript?

Back

A coefficient indicates the number of molecules, while a subscript indicates the number of atoms in a molecule.

Front

What is the total number of atoms in the reactants of the equation: 4Al + 3O2?

Back

7 (4 Al + 6 O = 10 total atoms).

Front

How do you determine the number of moles in a chemical reaction?

Back

You can determine the number of moles by using the coefficients in the balanced equation.