Q. The equivalent weight of a certain trivalent element is 20. Molecular weight of its oxide is
A) 152
B) 56
C) 168
D) 68
Explanation
(c)
Atomic weight of element,
$M =$equivalent weight$\times$valency
$= 20 \times 3$
$= 60$
Molecular formula of its oxide=$M_{2}O_{3}$
Hence, molecular weight of oxide
$= 2 \times 60 + 3 \times 16$
$= 120 + 48 = 168$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.