Calculate The Number Of Atoms, Including Subscripts, Coefficients, And Parentheses, In The Formula.The Formula Indicates There Are 2 Molecules Of $Al_2(SO_4)_3$.In This Molecule, There Are:- 4 Aluminum Atoms- 6 Sulfur Atoms- 24 Oxygen Atoms

Understanding the Basics of Chemical Formulas

Chemical formulas are a crucial aspect of chemistry, as they provide a concise representation of the composition of a molecule. A chemical formula consists of the symbols of the elements present in the molecule, along with their respective subscripts and coefficients. In this article, we will delve into the process of calculating the number of atoms in a chemical formula, including subscripts, coefficients, and parentheses.

The Formula: $Al_2(SO_4)_3$

The given formula is $Al_2(SO_4)_3$. This formula indicates that there are 2 molecules of $Al_2(SO_4)_3$. To calculate the number of atoms in this molecule, we need to break down the formula and understand the meaning of subscripts and coefficients.

Breaking Down the Formula

Let's start by breaking down the formula into its individual components:

• $Al_2$: This indicates that there are 2 aluminum atoms in the molecule.
• $(SO_4)_3$: This indicates that there are 3 molecules of $SO_4$ in the molecule. Each molecule of $SO_4$ contains 1 sulfur atom and 4 oxygen atoms.

Calculating the Number of Atoms

Now that we have broken down the formula, let's calculate the number of atoms in the molecule:

• Aluminum atoms: Since there are 2 molecules of $Al_2$, we need to multiply the number of aluminum atoms in each molecule by 2. Therefore, the total number of aluminum atoms is 2 x 2 = 4.
• Sulfur atoms: Since there are 3 molecules of $SO_4$, we need to multiply the number of sulfur atoms in each molecule by 3. Therefore, the total number of sulfur atoms is 3 x 1 = 3.
• Oxygen atoms: Since there are 3 molecules of $SO_4$, we need to multiply the number of oxygen atoms in each molecule by 3. Therefore, the total number of oxygen atoms is 3 x 4 = 12.

However, we are given that there are 24 oxygen atoms in the molecule. This means that the formula $Al_2(SO_4)_3$ actually represents 6 molecules of $SO_4$, not 3. Therefore, the correct calculation is:

• Aluminum atoms: 2 x 2 = 4
• Sulfur atoms: 6 x 1 = 6
• Oxygen atoms: 6 x 4 = 24

Conclusion

In conclusion, the formula $Al_2(SO_4)_3$ represents 6 molecules of $SO_4$, each containing 1 sulfur atom and 4 oxygen atoms. Therefore, the total number of atoms in the molecule is 4 aluminum atoms, 6 sulfur atoms, and 24 oxygen atoms.

Calculating the Number of Atoms in a Molecule with Subscripts and Coefficients

Subscripts and coefficients are used to indicate the number of atoms of each element in a molecule. Subscripts are used to indicate the number of atoms of an element that are present in a molecule, while coefficients are used to indicate the number of molecules of a compound that are present in a molecule.

Example 1: Calculating the Number of Atoms in a Molecule with Subscripts

The formula $CaCl_2$ represents a molecule that contains 1 calcium atom and 2 chlorine atoms. To calculate the number of atoms in this molecule, we need to multiply the number of atoms of each element by the subscript.

• Calcium atoms: 1 x 1 = 1
• Chlorine atoms: 1 x 2 = 2

Therefore, the total number of atoms in the molecule is 1 calcium atom and 2 chlorine atoms.

Example 2: Calculating the Number of Atoms in a Molecule with Coefficients

The formula $2NaCl$ represents a molecule that contains 2 sodium atoms and 2 chlorine atoms. To calculate the number of atoms in this molecule, we need to multiply the number of atoms of each element by the coefficient.

• Sodium atoms: 2 x 1 = 2
• Chlorine atoms: 2 x 1 = 2

Therefore, the total number of atoms in the molecule is 2 sodium atoms and 2 chlorine atoms.

Calculating the Number of Atoms in a Molecule with Parentheses

Parentheses are used to group atoms or molecules together. To calculate the number of atoms in a molecule with parentheses, we need to multiply the number of atoms of each element by the coefficient inside the parentheses.

Example 1: Calculating the Number of Atoms in a Molecule with Parentheses

The formula $(NH_3)_2$ represents a molecule that contains 2 molecules of $NH_3$. Each molecule of $NH_3$ contains 1 nitrogen atom and 3 hydrogen atoms. To calculate the number of atoms in this molecule, we need to multiply the number of atoms of each element by the coefficient inside the parentheses.

• Nitrogen atoms: 2 x 1 = 2
• Hydrogen atoms: 2 x 3 = 6

Therefore, the total number of atoms in the molecule is 2 nitrogen atoms and 6 hydrogen atoms.

Example 2: Calculating the Number of Atoms in a Molecule with Parentheses

The formula $(CO)_3$ represents a molecule that contains 3 molecules of $CO$. Each molecule of $CO$ contains 1 carbon atom and 1 oxygen atom. To calculate the number of atoms in this molecule, we need to multiply the number of atoms of each element by the coefficient inside the parentheses.

• Carbon atoms: 3 x 1 = 3
• Oxygen atoms: 3 x 1 = 3

Therefore, the total number of atoms in the molecule is 3 carbon atoms and 3 oxygen atoms.

Conclusion

Q: What is the difference between a subscript and a coefficient in a chemical formula?

A: A subscript is a small number written to the right of an element's symbol in a chemical formula, indicating the number of atoms of that element present in the molecule. A coefficient, on the other hand, is a number written in front of a formula of a compound, indicating the number of molecules of that compound present in the molecule.

Q: How do I calculate the number of atoms in a molecule with subscripts?

A: To calculate the number of atoms in a molecule with subscripts, you need to multiply the number of atoms of each element by the subscript. For example, in the formula $CaCl_2$, the subscript 2 indicates that there are 2 chlorine atoms for every 1 calcium atom.

Q: How do I calculate the number of atoms in a molecule with coefficients?

A: To calculate the number of atoms in a molecule with coefficients, you need to multiply the number of atoms of each element by the coefficient. For example, in the formula $2NaCl$, the coefficient 2 indicates that there are 2 sodium atoms and 2 chlorine atoms.

Q: How do I calculate the number of atoms in a molecule with parentheses?

A: To calculate the number of atoms in a molecule with parentheses, you need to multiply the number of atoms of each element by the coefficient inside the parentheses. For example, in the formula $(NH_3)_2$, the coefficient 2 inside the parentheses indicates that there are 2 molecules of $NH_3$, each containing 1 nitrogen atom and 3 hydrogen atoms.

Q: What is the order of operations when calculating the number of atoms in a molecule?

A: The order of operations when calculating the number of atoms in a molecule is as follows:

1. Multiply the number of atoms of each element by the subscript.
2. Multiply the number of atoms of each element by the coefficient.
3. Multiply the number of atoms of each element by the coefficient inside the parentheses.

Q: How do I determine the number of molecules of a compound present in a molecule?

A: To determine the number of molecules of a compound present in a molecule, you need to look for the coefficient in front of the formula of the compound. The coefficient indicates the number of molecules of that compound present in the molecule.

Q: What is the significance of subscripts and coefficients in a chemical formula?

A: Subscripts and coefficients are used to indicate the number of atoms of each element present in a molecule. They provide a concise representation of the composition of a molecule and are essential for understanding chemical reactions and stoichiometry.

Q: How do I apply the rules of subscripts and coefficients to calculate the number of atoms in a molecule?

A: To apply the rules of subscripts and coefficients, you need to follow these steps:

1. Identify the subscripts and coefficients in the chemical formula.
2. Multiply the number of atoms of each element by the subscript.
3. Multiply the number of atoms of each element by the coefficient.
4. Multiply the number of atoms of each element by the coefficient inside the parentheses.
5. Add up the total number of atoms of each element to determine the composition of the molecule.

Q: What are some common mistakes to avoid when calculating the number of atoms in a molecule?

A: Some common mistakes to avoid when calculating the number of atoms in a molecule include:

• Failing to multiply the number of atoms of each element by the subscript.
• Failing to multiply the number of atoms of each element by the coefficient.
• Failing to multiply the number of atoms of each element by the coefficient inside the parentheses.
• Not adding up the total number of atoms of each element to determine the composition of the molecule.

Conclusion

In conclusion, calculating the number of atoms in a chemical formula requires a thorough understanding of subscripts, coefficients, and parentheses. By following the steps outlined in this article and avoiding common mistakes, you can accurately calculate the number of atoms in a molecule and gain a deeper understanding of chemical formulas.