Counting Atoms Practice Set 1

Front

What is a coefficient in a chemical formula?

Back

A coefficient is a number placed in front of a chemical formula that indicates how many molecules of that substance are present.

Front

In the formula 4H₂O, what does the '4' represent?

Back

The '4' represents the number of water molecules (H₂O) present.

Front

How many atoms of Oxygen are in the formula Fe(NO₃)₃?

Back

There are 9 atoms of Oxygen in Fe(NO₃)₃.

Front

What does a subscript in a chemical formula indicate?

Back

A subscript indicates the number of atoms of the element in one molecule of the compound.

Front

In the formula 3(NH₄)₂CrO₄, how many Hydrogen atoms are there?

Back

There are 24 Hydrogen atoms in 3(NH₄)₂CrO₄.

Front

What does the subscript '2' in H₂O tell you?

Back

It tells you that there are 2 Hydrogen atoms in one molecule of water.

Front

What happens when you have a coefficient in front of a compound?

Back

It multiplies all the atoms in the compound by that number.

Front

How many total atoms are in the formula C₆H₁₂O₆?

Back

There are 24 total atoms in C₆H₁₂O₆ (6 Carbon + 12 Hydrogen + 6 Oxygen).

Front

What is the total number of atoms in 2H₂ + O₂?

Back

There are 6 total atoms (4 Hydrogen + 2 Oxygen).

Front

What does the formula NaCl represent?

Back

NaCl represents sodium chloride, which consists of 1 Sodium atom and 1 Chlorine atom.