- Using the moles of NaCl found in the previous question, determine how many grams of NaCl can be produced. mass of NaCl: 25.4 g
- Using the moles of NaCl found in a previous question, determine how many formula units of NaCl can be produced. formula units: 2.4 x1023
The Correct Answer and Explanation is :
To answer these questions, we’ll work through the calculations step by step.
1. Calculating Grams of NaCl Produced
Given:
- Moles of NaCl were already found in the previous question.
- The molar mass of NaCl is approximately 58.44 g/mol.
If the mass of NaCl produced is 25.4 g, then we use the relation:
[
\text{Moles of NaCl} = \frac{\text{Mass of NaCl}}{\text{Molar mass of NaCl}}
]
[
\text{Moles of NaCl} = \frac{25.4 \, \text{g}}{58.44 \, \text{g/mol}} \approx 0.435 \, \text{mol}
]
This confirms that 0.435 moles of NaCl correspond to 25.4 g of NaCl. Therefore, 25.4 g of NaCl is the mass that can be produced from 0.435 moles of NaCl.
2. Determining Formula Units of NaCl
Using the number of moles of NaCl (0.435 moles) and Avogadro’s number ((6.022 \times 10^{23}) formula units/mol):
[
\text{Formula units of NaCl} = \text{Moles of NaCl} \times \text{Avogadro’s number}
]
[
\text{Formula units of NaCl} = 0.435 \, \text{mol} \times 6.022 \times 10^{23} \, \text{formula units/mol}
]
[
\text{Formula units of NaCl} \approx 2.62 \times 10^{23}
]
Thus, 2.62 × 10²³ formula units of NaCl can be produced.
Explanation (300 Words)
The calculations rely on fundamental relationships in chemistry: the mole concept, molar mass, and Avogadro’s number. First, the molar mass of NaCl (58.44 g/mol) is used to convert between mass and moles. Knowing the mass of NaCl produced (25.4 g), we divide it by the molar mass to find the number of moles. This gives a direct measure of the amount of substance in moles.
Next, to determine the number of formula units (individual NaCl pairs), we use Avogadro’s number ((6.022 \times 10^{23}) formula units per mole). This constant establishes the number of entities in one mole of any substance. Multiplying the moles of NaCl (0.435 mol) by Avogadro’s number yields the total number of NaCl formula units produced. This approach shows how macroscopic amounts of material (grams) connect to the microscopic scale (atoms, molecules, or formula units).
These calculations are foundational in stoichiometry, where chemical reactions are analyzed quantitatively. Here, 25.4 g of NaCl corresponds to approximately 0.435 moles, which, when scaled up to formula units, equals 2.62 × 10²³ formula units. This process highlights how chemists translate theoretical concepts into real-world quantities, ensuring precise understanding and measurement.