To determine the correct answer, let's break down the concepts involved in the question:
1. Molecular Weight: This is the sum of the atomic weights of all atoms in a given molecule. For example, the molecular weight of water (H₂O) is approximately 18 grams per mole (2 grams for the hydrogen atoms and 16 grams for the oxygen atom).
2. Moles: A mole is a unit in chemistry used to express amounts of a chemical substance. One mole of any substance contains exactly 6.022 x 10²³ entities (such as atoms, molecules, or ions). This number is known as Avogadro's number.
3. Grams: This question specifies that we are dealing with the mass of a chemical that is equal to its molecular weight in grams. When the mass of a substance is equal to its molecular weight in grams, it means we have one mole of that substance.
4. Entities: The question mentions that this mass contains 6.023 x 10²³ molecules. This aligns with Avogadro's number, reinforcing that we are discussing a mole.
Considering the definitions provided:
- Ion: An ion is an atom or molecule with a net electrical charge due to the loss or gain of one or more electrons.
- Atomic Mass Unit (amu): This is a unit of mass used to express atomic and molecular weights (1 amu is 1/12 the mass of a carbon-12 atom).
- Molarity: This is a measure of the concentration of a solute in a solution, or how many moles of a solute are present per liter of solution.
- Mole: As described above, a mole is a unit that contains 6.022 x 10²³ entities and weighs as much in grams as the molecular weight of the substance.
Given that the mass in grams is equal to the molecular weight and contains approximately 6.022 x 10²³ molecules, the correct answer is:
d. mole
