Counting atoms and balancing equations

Front

What is the main purpose of balancing chemical equations?

Back

To ensure that the number of atoms of each element is the same on both sides of the equation.

Tags

NGSS.MS-PS1-5

Front

What does a coefficient in a chemical equation represent?

Back

The number of molecules or moles of a substance in a reaction.

Tags

NGSS.MS-PS1-5

Front

What do subscripts in a chemical formula indicate?

Back

The number of atoms of the element in one molecule of the compound.

Tags

NGSS.MS-PS1-1

Front

Is the equation H2 + O2 -> H2O balanced?

Back

No, it is not balanced.

Tags

NGSS.MS-PS1-5

Front

How do you determine if a chemical equation is balanced?

Back

By counting the number of atoms of each element on both sides of the equation.

Tags

NGSS.HS-PS1-7

Front

What is the first step in balancing a chemical equation?

Back

Write down the number of atoms of each element present in the reactants and products.

Front

What does it mean if a chemical equation is unbalanced?

Back

It means that the law of conservation of mass is not being followed.

Tags

NGSS.MS-PS1-5

Front

In the equation 2H2 + O2 -> 2H2O, what does the '2' in front of H2 and H2O represent?

Back

It represents that there are 2 molecules of hydrogen and 2 molecules of water.

Tags

NGSS.MS-PS1-5

Front

What is the significance of the law of conservation of mass in chemical reactions?

Back

It states that mass is neither created nor destroyed in a chemical reaction.

Tags

NGSS.MS-PS1-5

Front

What is the correct balanced form of the equation Al + HCl -> H2 + AlCl3?

Back

2Al + 6HCl -> 3H2 + 2AlCl3.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5