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S(s) + O2(g) –> SO2(g) DeltaH= -296kJ/mol a) How much heat is ev. when 275g sulfur...

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jokojoko | (Level 1) eNoter

Posted May 23, 2013 at 5:21 AM via iOS

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S(s) + O2(g) –> SO2(g) DeltaH= -296kJ/mol a) How much heat is ev. when 275g sulfur is burned in excess O2? How much heat is ev. when 25 molS is brnd?

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llltkl | College Teacher | (Level 3) Valedictorian

Posted May 23, 2013 at 5:42 AM (Answer #1)

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The balanced combustion reaction is

S(s) + O2(g) → SO2(g), ∆H= -296kJ/mol

From the stoichiometric ratio it can be said that,

When 1 mole = 32.065 g Sulfur is burnt in sufficient O2, 296 kJ energy is produced (atomic mass of S is 32.065).

Therefore, when 275g Sulfur is burnt in sufficient O2, amount of energy produced = 296*275/32.065 =  2538.593 kJ = 2538.6 kJ (approx.).

Again, when 1 mole Sulfur is burnt in sufficient O2, 296 kJ energy is produced.

Therefore, when 25 moles of Sulfur is burnt in sufficient O2, amount of energy produced = 296*25/1 = 7400 kJ.

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