Enthalpy of transition when amorphous boron [B(amorphous)] is converted into crystalline boron [B(crystalline)] is − 0.4 kcal 2 mole − 1 at 298 K . Calculate the heat change (in kcal ) when 247.5 gm o

Question

Enthalpy of transition when amorphous boron [B(amorphous)] is converted into crystalline boron [B(crystalline)] is $- 0.4 kcal^{2} mole^{- 1}$ at 298 K . Calculate the heat change (in kcal ) when 247.5 gm of crystalline boron is to be converted into amorphous form. (Atomic mass of boron $= 11$ ) at the same temperature.

Answer:

9

Solution:

B(crystalline) $⟶$ B(amorphous);

$Δ H = + 0.4 k c a l m o l^{- 1}$

for $247.5 g m = \frac{247.5}{11} \times 0.4 = 9$

TestHub · Accepted Answer

B(crystalline) ⟶ B(amorphous); Δ H = + 0.4 k c a l m o l − 1 for 247.5 g m = 11 247.5 ​ × 0.4 = 9

Chemistry - Thermochemistry Question with Solution | TestHub

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