Question

The equivalent mass of a trivalent metal element is 9 g eq⁻¹ the molar mass of its anhydrous oxide is
(a) 102 g
(b) 27 g
(c) 270 g
(d) 78 g

Answer 1

Answer is Option (a), 102 grams. 

Steps of the Calculations will be ---
Equivalent mass of the metal = 9 g eq⁻¹

As per as the Question, metal is trivalent, It means it can loose three electrons to complete its octet. 

∴ Atomic Mass of the Metal = 9 × 3
 = 27 grams.

Now, When the metal reacts with the Oxygen it will form Metal(III) oxide, Reaction will be,

4M + 3O₂ ------→ 2M₂O₃

Now, Molar mass of the Metal Oxide = At. mass of the Metal × 2  + At. mass of the Oxygen × 3
= 27 × 2 + 16 × 3
= 54 + 48
= 102 grams.


I hope it will help you.

Answer 2

Answer:

(a) 102 g Let the trivalent metal be M3+. Equivalent mass = (mass of the metal) / (valance factor) 9g eq-1 = mass of the metal / 3 eq Mass of the metal = 27 g Oxide formed M2 O3 Mass of the oxide = (2 × 27) + (3 × 16) = 102 gRead more on Sarthaks.com - https://www.sarthaks.com/914180/the-equivalent-mass-trivalent-metal-element-is-eq-the-molar-mass-its-anhydrous-oxide-is-102

Explanation:

hope it helps