standard enthalpy of formation of HI(g) is 26 kJ/mol

standard enthalpy of formation of HI(g) is 26 kJ/mol

 

 

The standard enthalpy of formation of HI(g) is 26 kJ/mol. Which of the following is the approximate mass of HI(g) that must decompose into H2(g) and I2(s) to release 500 kJ of energy?

 

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분해 반응식

HI(g) → 1/2 H2(g) + 1/2 I2(s) ... ΔH = -26 kJ/mol

( -부호는 에너지 방출, 즉 발열을 의미. )

( 아래 몰수를 계산할 때는 절대값만 사용. )

 

500 kJ / (26 kJ/mol) = 19.2308 mol HI 분해

 

HI의 몰질량 = 127.91 g/mol 이므로,

19.2308 mol × (127.91 g/mol) = 2459.8116 g HI

 

 

답: 2500 g