Which of the following will result in exactly 1.00 mole of sodium chloride (NaCl)?

• A. 23.00 g of NaCl
• B. 6.02 × 10^{23} molecules of NaCl
• C. 1.00 L of 1.00 M NaCl solution
• D. 58.44 g of NaCl

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the concept of a mole. One mole of any substance contains exactly \$6.022 \times 10^{23}\( entities (atoms, molecules, ions, etc.). For sodium chloride (NaCl), one mole corresponds to \)6.022 \times 10^{23}$ formula units of NaCl.
2. Step 2: Calculate the molar mass of NaCl by adding the atomic masses of sodium (Na) and chlorine (Cl). Sodium has an atomic mass of approximately 22.99 g/mol, and chlorine has an atomic mass of approximately 35.45 g/mol. So, \(M_{NaCl} = 22.99 + 35.45\) g/mol.
3. Step 3: Use the molar mass to relate grams of NaCl to moles. The number of moles is given by \(n = \frac{\text{mass (g)}}{M_{NaCl}}\). For example, 58.44 g of NaCl corresponds to \(\frac{58.44}{M_{NaCl}}\) moles.
4. Step 4: Understand the meaning of molarity (M). A 1.00 M NaCl solution contains 1.00 mole of NaCl per liter of solution. Therefore, 1.00 L of 1.00 M NaCl solution contains exactly 1.00 mole of NaCl.
5. Step 5: Recognize that \$6.022 \times 10^{23}$ molecules of NaCl represent exactly 1 mole of NaCl, and 58.44 g of NaCl corresponds to 1 mole based on the molar mass. However, 23.00 g of NaCl is less than 1 mole because it is less than the molar mass.