How many formula units are present in 351 g NaCl?
# formula units = mass/mass of 1 formula unit.
The mass of 1 formula unit is approximately 58.5 but you need to do it more accurately than that depending upon your instructions.
To determine the number of formula units in 351 g of NaCl, we need to use the molar mass of NaCl and Avogadro's number.
1. Find the molar mass of NaCl:
The molar mass of sodium (Na) is approximately 22.99 g/mol, and the molar mass of chlorine (Cl) is approximately 35.45 g/mol.
Thus, the molar mass of NaCl is:
22.99 g/mol (Na) + 35.45 g/mol (Cl) = 58.44 g/mol
2. Calculate the number of moles:
Moles = Mass / Molar mass
Moles = 351 g / 58.44 g/mol ≈ 6.01 mol
3. Determine the number of formula units:
Avogadro's number states that there are 6.022 × 10^23 particles in 1 mole of a substance.
Therefore, to find the number of formula units, multiply the number of moles by Avogadro's number:
Number of formula units = Moles × Avogadro's number
Number of formula units ≈ 6.01 mol × 6.022 × 10^23 particles/mol
Calculating this gives:
Number of formula units ≈ 3.62 × 10^24 formula units
So, there are approximately 3.62 × 10^24 formula units of NaCl in 351 g.
To determine the number of formula units in 351 g of NaCl, we need to use the concept of molar mass and Avogadro's number.
1. Find the molar mass of NaCl:
- The atomic mass of Na is 22.99 g/mol.
- The atomic mass of Cl is 35.45 g/mol.
- Adding these two masses together gives a molar mass of NaCl as 58.44 g/mol.
2. Calculate the number of moles of NaCl present:
- Divide the given mass (351 g) by the molar mass of NaCl (58.44 g/mol).
- 351 g ÷ 58.44 g/mol = 6.00 mol.
3. Use Avogadro's number to convert moles to formula units:
- Avogadro's number is approximately 6.022 × 10^23 formula units/mol.
- Multiply the number of moles (6.00 mol) by Avogadro's number.
- 6.00 mol × (6.022 × 10^23 formula units/mol) = 3.6132 × 10^24 formula units.
Therefore, there are approximately 3.6132 × 10^24 formula units of NaCl in 351 g.