The Element Oxygen Was Prepared by Joseph Priestley in 1774 $\rarr$

question 91

Multiple Choice

The element oxygen was prepared by Joseph Priestley in 1774 by heating mercury(II) oxide: HgO(s) $\rarr$ Hg(l) + ¹/₂O₂(g) , $\Delta$ H ^$\circ$ = 90.84 kJ/mol.Estimate the temperature at which this reaction will become spontaneous under standard state conditions.S ^$\circ$ (Hg) = 76.02 J/K·mol
S ^$\circ$ (O₂) = 205.0 J/K·mol
S ^$\circ$ (HgO) = 70.29 J/K·mol

• A) 108 K
• B) 430 K
• C) 620 K
• D) 775 K
• E) 840 K