A substance forms face-centred cubic crystals. Its density is $1.984gc{m}^{-3}$ and the edge length of the unit cell is $630pm$. Calculate the molar mass of the substance.

Q. Molybdenum forms body-centred cubic crystals whose density is $10.3gc{m}^{-3}$$.Calculatetheedgelengthoftheunitcell.Themolarmassof$Mo$is$95.94\ g\ mol^{-1}$.

Q. A solid having density of $9\times {10}^{3}kg.m^{-3}$ forms face centred cubic crystals of edge length $200\sqrt{2}pm$. What is the molar mass of the solid?
[Avogadro constant $\cong 6\times {10}^{23}mo{l}^{-1},\pi \cong 3$]

Q. Silver crystallises in a face-centred cubic in cell. The density of $Ag$ is $10.5gc{m}^{-3}$. Calculate the edge length of the unit cell.

Q. Nickel crystallizes in a face-centered cubic structure. If its density is $8.9$ g cm${}^{-3}$, then calculate the edge length (in $\mathring{A}$) of the unit cell.

Q. A crystalline solid of a pure substance has a face-centred cubic structure with a cell edge of 400 pm. If the density of the substance in the crystal is $8gc{m}^{-3},$ then the number of atoms present in 256 g of the crystal is $N\times {10}^{24}$. The value of N is