Question

Which weighs more, 0.50 mol of oxygen atoms or 4 mol of hydrogen atoms?

Short answer

\(0.50~mol\) of oxygen atoms weigh more than \(4~mol\) of hydrogen atoms, with the respective masses being 8 g and 4 g.

Step-by-step solution

Write down the provided information

We are given the following information: - 0.50 mol of oxygen atoms - 4 mol of hydrogen atoms

Recall the atomic masses of oxygen and hydrogen

- Oxygen (O) has an atomic mass of 16 g/mol. - Hydrogen (H) has an atomic mass of 1 g/mol.

Calculate the mass of 0.50 mol of oxygen atoms

To find the mass of oxygen atoms, we will multiply the given number of moles by the atomic mass of oxygen: Mass (O) = 0.50 mol * 16 g/mol

Calculate the mass of 4 mol of hydrogen atoms

To find the mass of hydrogen atoms, we will multiply the given number of moles by the atomic mass of hydrogen: Mass (H) = 4 mol * 1 g/mol

Compare the two masses

Now that we have the masses of both oxygen and hydrogen atoms in the given quantity, we will compare their sizes to determine which one is greater. Mass (O) = 0.50 mol * 16 g/mol = 8 g Mass (H) = 4 mol * 1 g/mol = 4 g Since 8 g (oxygen) > 4 g (hydrogen), we can conclude that 0.50 mol of oxygen atoms weigh more than 4 mol of hydrogen atoms.

Key concepts

Mole Concept

The mole is one of the most fundamental concepts in chemistry, acting as a bridge between the microscopic world of atoms and molecules and the macroscopic world of grams and liters. One mole is defined as exactly 6.022 x 10²³ particles, which is Avogadro's number. This extensive quantity provides a way to convert between the number of particles and the easily measurable mass of a substance.

For example, in the given exercise, we are comparing 0.50 moles of oxygen atoms with 4 moles of hydrogen atoms. Understanding the mole concept allows us to quantify these substances and subsequently compare which one weighs more. The ability to count by weighing is incredibly useful in a laboratory setting, as it’s virtually impossible to count each atom one by one.

Atomic Mass

The atomic mass, also known as atomic weight, is the mass of a single atom of a chemical element. It is expressed in atomic mass units (u), where one atomic mass unit is defined as one-twelfth of the mass of an atom of carbon-12. In practical chemistry, atomic masses are usually given in grams per mole (g/mol), allowing chemists to work with macroscopic amounts instead of individual atoms.

For instance, in our exercise, the atomic mass of oxygen is given as 16 g/mol and of hydrogen as 1 g/mol. By using these atomic masses, we can calculate the total mass of any quantity of atoms in grams provided we know the number of moles, thus facilitating comparisons like the one in the exercise.

Stoichiometry

Stoichiometry is the area of chemistry that deals with the quantitative relationships between reactants and products in a chemical reaction. It makes use of the balanced chemical equations to calculate the masses, volumes, and number of moles of substances involved. Understanding stoichiometry is crucial for making solutions, predicting product yields, and scaling reactions up or down.

Relating to our problem, stoichiometry can be applied to determine the mass of elements based on the stoichiometric coefficients of the substances involved. Although the exercise does not directly involve a chemical reaction, the concept of stoichiometry is still applied to calculate the mass of elements from their respective molar quantities, which is key in comparing the atomic masses.