Q6 Consider the reaction at 300 K H2g + Cl2g →2HClg - Chemistry - Thermodynamics and Thermochemistry

Question

Q6 Consider the reaction at 300 K
H 2 g   +   C l 2 g   → 2 H C l g  
                 
∆ H ° = - 185   k J
If 3 moles of H2 completely react with mole of
Cl2 to form HCl What is ∆ U ° the for this
reaction ?
(A) 0 (B) -185 kJ (C) 555 kJ (D) None of these

Vartika Jain · Accepted Answer

Dear Student,

We know that,∆H°=∆U° +∆nRTFor the reaction, H2(g) + Cl2(g) → 2HCl(g)1 mol of H2 and Cl2 gives 2 mol of HClSo, 3 mol of H2 and Cl2 gives 3×2=6 mol of HCl∆ng = moles of gaseous products-moles of gaseous reactants         = 6-(3+3)         =6-6         =0So, ∆U°=∆H°=-185 kJHence, correct answer is (B)

Q6. Consider the reaction at 300 K H 2 g + C l 2 g → 2 H C l g ∆ H ° = - 185 k J If 3 moles of H2 completely react with mole of Cl2 to form HCl. What is ∆ U ° the for this reaction ? (A) 0 (B) -185 kJ (C) 555 kJ (D) None of these

Q6. Consider the reaction at 300 K
$H_{2} (g) + C l_{2} (g) \to 2 H C l (g) ∆ H ° = - 185 k J$
If 3 moles of H₂ completely react with mole of Cl₂ to form HCl. What is $∆ U °$ the for this reaction ?
(A) 0 (B) -185 kJ (C) 555 kJ (D) None of these