Q20 / 160 · AP EAMCET 2023 (19 May Shift 1) · Chemistry

In a $A_x B_y$ crystal structure, $A^{+y}$ ions occupy all the tetrahedral voids and $\mathrm{B}^{-\mathrm{x}}$ ions make $\mathrm{BCC}$ unit cell: What is the formula of the compound?

  • Correct answer
    A
    $\mathrm{A}_4 \mathrm{~B}_2$
  • B
    $\mathrm{A}_2 \mathrm{~B}_4$
  • C
    $\mathrm{A}_2 \mathrm{~B}_2$
  • D
    $\mathrm{A}_4 \mathrm{~B}_4$

Solution

Number of $\mathrm{A}^{+\mathrm{y}}$ ions $=2 \times$ number of atoms per unit cell. Number of $\mathrm{B}^{-\mathrm{x}}$ ions $=2(\mathrm{BCC})$ per unit cell. $\Rightarrow$ Number of $\mathrm{A}^{+\mathrm{y}}$ ions $=2 \times 2=4$ $\Rightarrow$ Formula $=\mathrm{A}_4 \mathrm{~B}_2$

Hence, the correct answer is option: 'A'.

Relevant Questions