반응형 일반화학/[05장] 열화학395 ΔH 계산. 2Al(s) + Fe2O3(s) → Al2O3(s) + 2Fe(s) ΔH 계산. 2Al(s) + Fe2O3(s) → Al2O3(s) + 2Fe(s) 생성엔탈피로 반응엔탈피 계산. 2Al(s) + Fe2O3(s) --------------------------------------------------- ΔH°_rxn = [생성물들의 ΔH°_f 합] – [반응물들의 ΔH°_f 합] ( 참고 https://ywpop.tistory.com/3431 ) = [(–1675.5) + 2(0)] – [2(0) + (–824.2)] ( 참고: ΔH°_f 값 https://en.wikipedia.org/wiki/Standard_enthalpy_of_formation ) = –851.3 kJ 답: –851.3 kJ [ 관련 예제 https://ywpop.tistory.com/11750 ].. 2023. 7. 9. 결합에너지로 반응엔탈피 계산. 2CO + O2 → 2CO2 결합에너지로 반응엔탈피 계산. 2CO + O2 → 2CO2 결합에너지로 반응엔탈피 계산. 2CO(g) + O2(g) → 2CO2(g) ※ 결합 에너지 (kJ/mol) C=O: 799, C≡O: 1072, O=O: 498 --------------------------------------------------- ▶ 참고: 결합 엔탈피로 반응 엔탈피 계산 [ https://ywpop.tistory.com/3729 ] --------------------------------------------------- 모든 결합이 절단되고 나서 모든 결합이 새로 생성된다고 생각하면, Σ(절단 결합의 결합 엔탈피) = 2(C≡O) + (O=O) = 2(1072) + (498) = 2642 kJ CO2 ---> O=C=.. 2023. 6. 28. 반응엔탈피로 결합에너지 계산. O–H bond energy 반응엔탈피로 결합에너지 계산. O–H bond energy 열화학 반응식을 이용하여 O–H 결합 에너지 계산 H2(g) + 1/2 O2(g) → H2O(g) ... ΔH = –241.8 kJ H2(g) → 2H(g) ... ΔH = 435.8 kJ O2(g) → 2O(g) ... ΔH = 498.6 kJ --------------------------------------------------- ▶ 참고: 결합 엔탈피로 반응 엔탈피 계산 [ https://ywpop.tistory.com/3729 ] --------------------------------------------------- H2(g) → 2H(g) ... ΔH = 435.8 kJ O2(g) → 2O(g) ... ΔH = 498.6 kJ .. 2023. 6. 21. 0.250 L 0.980 L 136.8 kPa expand work (J) 0.250 L 0.980 L 136.8 kPa expand work (J) A fuel is burned in a cylinder equipped with a piston. The initial volume of the cylinder is 0.250 L, and the final volume is 0.980 L. If the piston expands against a constant pressure of 136.8 kPa, how much work (in J) is done? --------------------------------------------------- w = –PΔV ( 참고 https://ywpop.tistory.com/6336 ) = –(136800 Pa) (0.980 – 0.25.. 2023. 6. 20. ΔH 계산. C(graphite) → C(diamond) ΔH 계산. C(graphite) → C(diamond) 다이아몬드의 생성열. 다이아몬드의 생성엔탈피 standard enthalpy of formation of diamond 1) C(diamond) + O2(g) → CO2(g) ... ΔH = –395.4 kJ 2) C(graphite) + O2(g) → CO2(g) ... ΔH = –393.5 kJ * 나머지 2개의 반응식은 없어도 된다. --------------------------------------------------- ▶ 참고: 헤스의 법칙. Hess’s Law [ https://ywpop.tistory.com/3376 ] ※ 헤스의 법칙을 이용한 이런 유형의 문제는 간단한 원리만 이해하면, 끼워 맞추기 ‘놀이’에 불과하다. 다이아몬드.. 2023. 6. 16. 125 g water 283 g 3.0℃ 91.0℃ 125 g water 283 g 3.0℃ 91.0℃ A 125 g sample of cold water and a 283 g sample of hot water are mixed in an insulated thermos bottle and allowed to equilibrate. If the initial temperature of the cold water is 3.0℃, and the initial temperature of the hot water is 91.0℃, what will be the final temperature? --------------------------------------------------- ▶ 참고: 열용량과 비열 [ https://ywpop.tistory.com/.. 2023. 6. 16. 구리의 몰열용량. 226 kJ heat Cu 47.0 kg 12.5℃ 구리의 몰열용량. 226 kJ heat Cu 47.0 kg 12.5℃ If 226 kJ of heat increases the temperature of 47.0 kg of copper by 12.5℃, what is the molar heat capacity of copper? --------------------------------------------------- ▶ 참고: 열용량과 비열 [ https://ywpop.tistory.com/2897 ] --------------------------------------------------- q = C m Δt 로부터, C = q / [m Δt] = (226 kJ) / [47.0 kg × 12.5 ℃] = 0.385 kJ/kg•℃ = 0.385 J.. 2023. 6. 16. 생성엔탈피로 반응엔탈피 계산. CH4(g) 불완전 연소열 생성엔탈피로 반응엔탈피 계산. CH4(g) 불완전 연소열 ΔH 계산. 2CH4(g) + 3O2(g) → 2CO(g) + 4H2O(l) --------------------------------------------------- CH4 불완전 연소 반응식 2CH4(g) + 3O2(g) → 2CO(g) + 4H2O(l) ( 참고 https://ywpop.tistory.com/11595 ) ΔH°_rxn = [생성물들의 ΔH°_f 합] – [반응물들의 ΔH°_f 합] ( 참고 https://ywpop.tistory.com/3431 ) = [2(–110.525) + 4(–285.8)] – [2(–74.9) + 3(0)] ( 참고: ΔH°_f 값 https://en.wikipedia.org/wiki/Standar.. 2023. 6. 16. ΔE 계산. 1.90 atm 8.30 L 2.80 L 350.0 J heat internal energy ΔE 계산. 1.90 atm 8.30 L 2.80 L 350.0 J heat internal energy A piston is compressed from a volume of 8.30 L to 2.80 L against a constant pressure of 1.90 atm. In the process, there is a heat gain by the system of 350.0 J. Calculate the internal energy change. --------------------------------------------------- w = –PΔV ( 참고 https://ywpop.tistory.com/5281 ) = –(1.90) (2.80 – 8.30) = +10.45 atm•L (+.. 2023. 6. 14. gold 55.5 g temp 20℃ 45℃ increase heat gold 55.5 g temp 20℃ 45℃ increase heat What quantity of heat is required to raise the temperature of 55.5 g of gold from 20℃ to 45℃? The specific heat of gold is 0.13 J/g•℃. --------------------------------------------------- ▶ 참고: 열용량과 비열 [ https://ywpop.tistory.com/2897 ] --------------------------------------------------- q = C m Δt = (0.13 J/g•℃) (55.5 g) (45 – 20 ℃) = (0.13) (55.5) (45 – 20.. 2023. 6. 11. 이전 1 2 3 4 5 6 ··· 40 다음 반응형
