What is the molecular weight of carbon dioxide? 44 g/mol
The Correct Answer and Explanation is:
Correct Answer: The molecular weight of carbon dioxide (CO₂) is 44 g/mol.
Explanation:
Molecular weight, also known as molecular mass, is the sum of the atomic masses of all the atoms in a molecule. To find the molecular weight of carbon dioxide (CO₂), we need to look at the atomic composition of the molecule and use the atomic weights of each element involved.
Carbon dioxide consists of one carbon atom and two oxygen atoms. The atomic masses of these elements, based on the periodic table, are approximately:
- Carbon (C) = 12 g/mol
- Oxygen (O) = 16 g/mol
Now, since the formula for carbon dioxide is CO₂, we calculate its molecular weight by summing the mass of one carbon atom and two oxygen atoms:
- Carbon: 1 × 12 g/mol = 12 g/mol
- Oxygen: 2 × 16 g/mol = 32 g/mol
Now, add the two values:
- Total molecular weight = 12 g/mol + 32 g/mol = 44 g/mol
This value tells us that one mole of carbon dioxide molecules has a mass of 44 grams. This is a crucial number in chemistry because it allows chemists to relate the number of molecules of CO₂ to a measurable mass in grams.
For example, if a chemist needs 2 moles of CO₂ for a reaction, they would need 88 grams of it. The concept of molecular weight is essential for stoichiometry, which involves calculations of reactants and products in chemical reactions.
Molecular weight is also used in gas laws, where understanding the mass and volume relationship of gases at different conditions depends on accurate molecular weight values. Thus, knowing that carbon dioxide has a molecular weight of 44 g/mol is foundational for both practical and theoretical chemistry.
