Question:
Two ions $A^+$ and $B^-$ have radii 104 and 200 pm respectively, in a cubic close packed crystal of compound AB. The co-ordination no. of A is
Two ions $A^+$ and $B^-$ have radii 104 and 200 pm respectively, in a cubic close packed crystal of compound AB. The co-ordination no. of A is
Updated On: May 12, 2024
- 4
- 8
- 6
- 3
Hide Solution
Verified By Collegedunia
The Correct Option is C
Solution and Explanation
Radius ratio= $\frac{r_+}{r_-} = \frac{104 \, pm}{200 \, pm} = 0.52$ As it lies in the range 0.414 - 0.732, the coordination number will be 6
Was this answer helpful?
0
0
Top Questions on Unit Cells
- Which of the following statements is incorrect for antibiotics?
- JEE Main - 2023
- Chemistry
- Unit Cells
- Which of the following expressions is correct in case of a CSCl unit cell (edge length, a) ?
- JEE Main - 2023
- Chemistry
- Unit Cells
- The correct option for the number of body centred unit cells in all $14$ types of Bravais lattice unit cells is :
- NEET (UG) - 2021
- Chemistry
- Unit Cells
- Right option for the number of tetrahedral and octahedral voids in hexagonal primitive unit cell are:
- NEET (UG) - 2021
- Chemistry
- Unit Cells
- The ratio of number of atoms present in a simple cubic, body centered cubic and face centered cubic structure are, respectively :
- JEE Main - 2019
- Chemistry
- Unit Cells
View More Questions
Questions Asked in COMEDK UGET exam
- A $2\,kg$ mass lying on a table is displaced in the horizontal direction through $50\,cm$. The work done by the normal reaction will be
- COMEDK UGET - 2015
- work, energy and power
- The numbers of $ {H^+}$ ions present in 1 mL of a solution whose pH is 13
- COMEDK UGET - 2015
- Equilibrium
- A mixture of methylamine and dimethylamine is given to you. The reagents used to separate the components of the mixture are
- $\cot^{-1} (21) + \cot^{-1} (13) + \cot^{-1} (-8) =$
- COMEDK UGET - 2015
- Inverse Trigonometric Functions
- Pick the incorrect statement among those given below.
- COMEDK UGET - 2015
- Chemical bonding and molecular structure
View More Questions
Concepts Used:
Unit Cells
The smallest portion of a crystal lattice which repeats in different directions to form the entire lattice is known as Unit cell.
The characteristics of a unit cell are:
- The dimensions are measured along the three edges, a, b and c. These edges can form different angles, they may be mutually perpendicular or may not.
- The angles held by the edges are α (between b and c) β (between a and c) and γ (between a and b).
Therefore, a unit cell is characterised by six parameters such as a, b, c and α, β, γ.
Types of Unit Cell:
Numerous unit cells together make a crystal lattice. Constituent particles like atoms, molecules are also present. Each lattice point is occupied by one such particle.
- Primitive Unit Cells: In a primitive unit cell constituent particles are present only on the corner positions of a unit cell.
- Centred Unit Cells: A centred unit cell contains one or more constituent particles which are present at positions besides the corners.
- Body-Centered Unit Cell: Such a unit cell contains one constituent particle (atom, molecule or ion) at its body-centre as well as its every corners.
- Face Centered Unit Cell: Such a unit cell contains one constituent particle present at the centre of each face, as well as its corners.
- End-Centred Unit Cells: In such a unit cell, one constituent particle is present at the centre of any two opposite faces, as well as its corners.