JEE Advanced · Chemistry · 15. Solid State
The edge length of unit cell of a metal having molecular weight \(75 \mathrm{~g} / \mathrm{mol}\) is 5 Å which crystallizes in cubic lattice. If the density is \(2 \mathrm{~g} / \mathrm{cc}\) then find the radius of metal atom, \(\left(N_A=6 \times 10^{23}\right)\). Give the answer in pm.
- A 216.5
- B 214.55
- C 341.55
- D 102.88
Answer & Solution
Correct Answer
(A) 216.5
Step-by-step Solution
Detailed explanation
For cubic lattice, \(\rho=\frac{Z \times A}{N_A \times V}\) or \(Z=\frac{\rho \times N_A \times V}{A}\)
Given that,
\(A=75 \mathrm{~g} / \mathrm{mol} \)
\( V=(5 Å)^3=\left(5 \times 10^{-8}\right)^3 \mathrm{~cm}^3 \)
\( =125 \times 10^{-24} \mathrm{~cm}^3 \)
\( N_{\mathrm{A}}=6.02 \times 10^{23} \)
\( \rho=2 \mathrm{gm} / \mathrm{cc} \)
\( \therefore Z=\frac{2 \times 6.02 \times 10^{23} \times 125 \times 10^{-24}}{75} \approx 2\)
The value of \(Z\) represents that element must have body centred cubic (bcc) structure.
For bcc structure atomic radius \((r)=\frac{\sqrt{3}}{4} a=\frac{\sqrt{3}}{4} \times 5=2.165 Å\)
\(
=216.5 \mathrm{pm}
\)
Given that,
\(A=75 \mathrm{~g} / \mathrm{mol} \)
\( V=(5 Å)^3=\left(5 \times 10^{-8}\right)^3 \mathrm{~cm}^3 \)
\( =125 \times 10^{-24} \mathrm{~cm}^3 \)
\( N_{\mathrm{A}}=6.02 \times 10^{23} \)
\( \rho=2 \mathrm{gm} / \mathrm{cc} \)
\( \therefore Z=\frac{2 \times 6.02 \times 10^{23} \times 125 \times 10^{-24}}{75} \approx 2\)
The value of \(Z\) represents that element must have body centred cubic (bcc) structure.
For bcc structure atomic radius \((r)=\frac{\sqrt{3}}{4} a=\frac{\sqrt{3}}{4} \times 5=2.165 Å\)
\(
=216.5 \mathrm{pm}
\)
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Chemistry
- The correct statement(s) about surface properties is(are)JEE Advanced 2017 Easy
- The boiling point of water in a \(0.1\) molal silver nitrate solution (solution \(\mathbf{A}\) ) is \(\mathbf{x}^{\circ} \mathrm{C}\). To this solution \(\mathbf{A}\), an equal volume of \(0.1\) molal aqueous barium chloride solution is added to make a new solution B. The difference in the boiling points of water in the two solutions \(\mathbf{A}\) and \(\mathbf{B}\) is \(\mathbf{y} \times 10^{-2}{ }^{\circ} \mathrm{C}\).
(Assume: Densities of the solutions \(\mathbf{A}\) and \(\mathbf{B}\) are the same as that of water and the soluble salts dissociate completely.
Use: Molal elevation constant (Ebullioscopic Constant), \(K_{b}=0.5 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}\); Boiling point of pure water as \(100^{\circ} \mathrm{C}\).)
The value of is ___.JEE Advanced 2021 Hard - The molar conductivity of a solution of a weak acid HX (0.01 M) is 10 times smaller than the molar conductivity of a solution of a weak acid HY (0.10 M). If , the difference in their values, , is (Consider degree of ionization of both acids to << 1)JEE Advanced 2015 Hard
- The correct statement about the following disaccharide is
JEE Advanced 2010 Medium - The species having pyramidal shape isJEE Advanced 2010 Hard
- In the following reactions, P, Q, R and S are the major products.

The correct statement(s) about P, Q, R and S is(are)JEE Advanced 2023 Hard
More PYQs from JEE Advanced
- The value of is equal toJEE Advanced 2016 Hard
- Paragraph:
Let \(S=S_{1} \cap S_{2} \cap S_{3}\), where
\(S_{1}=\{z \in \mathbb{C}:|z|<4\}, \quad S_{2}=\left\{z \in \mathbb{C}: \operatorname{Im}\left[\frac{z-1+\sqrt{3} i}{1-\sqrt{3} i}\right]>0\right\}\) and \(S_{3}=\{z \in \mathbb{C}: \operatorname{Re} z>0\}\).
Question:
Area of \(S=\)JEE Advanced 2013 Medium - The number of neutrons emitted when \({ }_{92}^{235} \mathrm{U}\) undergoes controlled nuclear fission to \({ }_{54}^{142} \mathrm{Xe}\) and \({ }_{38}^{90} \mathrm{Sr}\) isJEE Advanced 2010 Medium
- One mole of an ideal gas expands adiabatically from an initial state to final state . Another mole of the same gas expands isothermally from a different initial state to the same final state . The ratio of the specific heats at constant pressure and constant volume of this ideal gas is . What is the ratio ?JEE Advanced 2023 Easy
- Among PbS, CuS, HgS, MnS, , NiS, CoS, and , the total number of black coloured sulphides isJEE Advanced 2014 Easy
- Statement I Glucose gives a reddish-brown precipitate with Fehling's solution.
Statement II Reaction of glucose with Fehling's solution gives \(\mathrm{CuO}\) and gluconic acid.JEE Advanced 2007 Medium