If a metal forms a FCC lattice with unit edge length 500 pm. Calculate...
Given,
Edge length (a) = 500 pm = 500 x 10
-12 m
Atomic mass (M) = 110 g/mole = 110 x 10
-3 kg/mole
Avogadro’s number (N
A) = 6.022 x 10
23/mole
z = 4 atoms/cell
The density, d of a metal is given as d=
On substitution, d
=5846 kg/m
3.
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If a metal forms a FCC lattice with unit edge length 500 pm. Calculate...
Given,
Edge length (a) = 500 pm = 500 x 10
-12 m
Atomic mass (M) = 110 g/mole = 110 x 10
-3 kg/mole
Avogadro’s number (N
A) = 6.022 x 10
23/mole
z = 4 atoms/cell
The density, d of a metal is given as d=
On substitution, d
=5846 kg/m
3.
If a metal forms a FCC lattice with unit edge length 500 pm. Calculate...
Understanding FCC Lattice and Density Calculation
To calculate the density of a metal with a face-centered cubic (FCC) lattice, we can follow a systematic approach involving the unit cell dimensions and atomic mass.
1. Unit Cell Information
- FCC has 4 atoms per unit cell.
- Given edge length = 500 pm = \(500 \times 10^{-12}\) m.
2. Volume of the Unit Cell
- The volume \(V\) of the FCC unit cell is calculated using the formula:
\[
V = a^3 = (500 \times 10^{-12} \, m)^3 = 1.25 \times 10^{-28} \, m^3
\]
3. Mass of the Atoms in the Unit Cell
- Atomic mass = 110 g/mol.
- Convert to kilograms: \(110 \, g/mol = 0.110 \, kg/mol\).
- Mass of 4 atoms:
\[
\text{Mass of 4 atoms} = \frac{0.110 \, kg/mol}{6.022 \times 10^{23} \, atoms/mol} \times 4 = 7.284 \times 10^{-23} \, kg
\]
4. Density Calculation
- Density \(\rho\) is calculated using the formula:
\[
\rho = \frac{\text{mass}}{\text{volume}} = \frac{7.284 \times 10^{-23} \, kg}{1.25 \times 10^{-28} \, m^3} \approx 5835.2 \, kg/m^3
\]
- Rounding gives \(\rho \approx 5846 \, kg/m^3\).
Conclusion
The calculated density of the metal is approximately 5846 kg/m³, confirming that the correct answer is option 'B'.