To answer the question of how 1 mole of sodium chloride (NaCl) compares to 1 mole of aluminum chloride (AlCl₃), we need to consider several key properties of these compounds.
### Molar Mass
First, let's analyze the molar mass:
- Sodium chloride (NaCl): The molar mass is calculated by adding the atomic masses of sodium (Na) and chlorine (Cl):
- Na = 22.99 g/mol
- Cl = 35.45 g/mol
- Molar mass of NaCl = 22.99 + 35.45 = 58.44 g/mol
- Aluminum chloride (AlCl₃): The molar mass is calculated by adding the atomic mass of aluminum (Al) and three times the atomic mass of chlorine (Cl):
- Al = 26.98 g/mol
- Cl = 35.45 g/mol
- Molar mass of AlCl₃ = 26.98 + (3 × 35.45) = 26.98 + 106.35 = 133.33 g/mol
Since the molar masses are different, the statement "Both have the same molar mass" is incorrect.
### Number of Ions
Next, let's look at the number of ions:
- Sodium chloride (NaCl) dissociates into 2 ions:
- 1 Na⁺ ion
- 1 Cl⁻ ion
- Aluminum chloride (AlCl₃) dissociates into 4 ions:
- 1 Al³⁺ ion
- 3 Cl⁻ ions
Therefore, since the number of ions produced in solution differs, the statement "Both have the same number of ions" is incorrect.
### Molecules vs. Formula Units
It is important to note that both NaCl and AlCl₃ are ionic compounds, not molecular compounds. Hence, they do not consist of discrete molecules but rather of formula units. One formula unit of NaCl consists of one Na⁺ and one Cl⁻ ion, and one formula unit of AlCl₃ consists of one Al³⁺ ion and three Cl⁻ ions.
- 1 mole of any substance contains 6.02 × 10²³ entities, based on Avogadro's number.
- For ionic compounds, these entities are called formula units.
So, 1 mole of NaCl contains 6.02 × 10²³ formula units of NaCl, and 1 mole of AlCl₃ contains 6.02 × 10²³ formula units of AlCl₃. Thus, the statement "Both are made up of [tex]$6.02 \times 10^{23}$[/tex] formula units" is correct.
With this detailed analysis, the correct comparison is:
Both are made up of \[tex]$6.02 \times 10^{23}\$[/tex] formula units.
