Question

There are ________ molecules of methane in 0.123 mol of methane (CH₄).

Answer 1

The number of methane molecules in 0.123 mol of methane is 7.407 × 1022 molecules, calculated using Avogadro's number.

Step-by-step explanation:

To calculate the number of methane molecules in 0.123 mol of methane (CH4), we use Avogadro's number, which states that one mole of any substance contains 6.022 × 1023 entities (atoms, ions, molecules, etc.). Therefore, the number of molecules in 0.123 mol of methane is:

0.123 mol × (6.022 × 1023 molecules/mol) = 7.407 × 1022 methane molecules.

This reflects the foundational concept of mole-to-entity conversion in chemistry. Remembering that methane is a simple hydrocarbon with a tetrahedral geometry, each molecule consists of one carbon atom bonded to four hydrogen atoms, with angle of 109.5° between them.