The heat of formation of MgO, Al 2 O 3 and SiO 2 are -692,-1676, -911, kJ mol -1. Most stable oxide is:

Question

The heat of formation of MgO, Al 2 O 3 and SiO 2 are -692,-1676, -911, kJ mol -1. Most stable oxide is: (A)  MgO  (B)  Al2O3 (C)  SiO2 (D) cannot be predicted

Tardigrade Admin · Accepted Answer

A smaller higher charged ion will be closer to the oxide ions ( O 2-), which means the thermal stability of MgO is more or it takes more energy to break the crystal structure of MgO

Q. The heat of formation of $M g O, A l_{2} O_{3}$ and $S i O_{2}$ are $- 692, - 1676, - 911, k J m o l^{- 1}$ . Most stable oxide is:

$M g O$

$A l_{2} O_{3}$

$S i O_{2}$

cannot be predicted

A smaller higher charged ion will be closer to the oxide ions $(O^{2 -})$ , which means the thermal stability of $M g O$ is more or it takes more energy to break the crystal structure of $M g O$

Q. The heat of formation of MgO,Al2​O3​ and SiO2​ are −692,−1676,−911,kJmol−1. Most stable oxide is:

MgO

Al2​O3​

SiO2​