반응형 일반화학/[05장] 열화학395 ethanol vapor 25.0 g 93.0℃ -11.0℃ energy kJ ethanol vapor 25.0 g 93.0℃ -11.0℃ energy kJ 에탄올 증기 25.0 g을 93.0 ℃에서 –11.0 ℃로 응축시킬 때방출되는 에너지는 몇 kJ인가?에탄올의 mp는 –114.1 ℃, bp는 78.3 ℃,ΔH_증발는 38.56 kJ/mol, ΔH_용융는 4.93 kJ/mol이다.액체 에탄올의 몰열용량은 112.3 J/(K•mol)이고,에탄올 증기의 몰열용량은 65.6 J/(K•mol)이다. How much energy in kJ is released when 25.0 g of ethanol vapor at 93.0 °C is cooled to –11.0 °C? --------------------------------------------------- .. 2024. 6. 14. 1.0 L water Al pan 0.20 kg 20℃ boil energy heat 0.90 J/g-K 1.0 L water Al pan 0.20 kg 20℃ boil energy heat 0.90 J/g-K 1.0 L 물이 담긴 알루미늄 프라이팬(0.20 kg)을 가열한다면, 상온(20 ℃)에서 끓을 때까지 얼마나 많은 에너지(열)가 필요한가? 팬과 물 사이에 열적 평형은 항상 유지된다고 가정한다(Al과 H2O의 비열은 0.90 J/g-K과 4.18 J/g-K이다. 물의 밀도는 1 g/mL이다). How much energy (heat) does it take to heat an Al saucepan (0.20 kg) containing 1.0 L of water from room temperature (20 ℃) to boiling? Assume thermal equilibrium b.. 2024. 6. 13. ΔH 계산. Pb(s) + PbO2(s) + 2SO3(g) → 2PbSO4(s) ΔH 계산. Pb(s) + PbO2(s) + 2SO3(g) → 2PbSO4(s) 다음 정보를 사용하여Pb(s) + PbO2(s) + 2H2SO4(l) → 2PbSO4(s) + 2H2O(l) ... ΔH° = –509.2 kJ/molSO3(g) + H2O(l) → H2SO4(l) ... ΔH° = –130.3 kJ/mol 다음 반응에 대한 ΔH°를 계산하라.Pb(s) + PbO2(s) + 2SO3(g) → 2PbSO4(s) determine ΔH° for the following thermochemical equation.Pb(s) + PbO2(s) + 2SO3(g) → 2PbSO4(s) --------------------------------------------------- .. 2024. 6. 10. 1.252 g cyclohexanol C6H12O 27.00℃ to 31.11℃ 11.3 kJ/℃ 1.252 g cyclohexanol C6H12O 27.00℃ to 31.11℃ 11.3 kJ/℃ A 1.252 g sample of cyclohexanol (C6H12O) was burned in a constant-volume bomb calorimeter where the temperature of the water increased from 27.00℃ to 31.11℃. If the heat capacity of the bomb plus water is 11.3 kJ/℃, what is the molar heat of combustion of cyclohexanol? --------------------------------------------------- 답: ΔH = –37.. 2024. 6. 8. BaCl2 fireworks bright green 1 mol 15.00 g BaCl2 ΔH BaCl2 fireworks bright green 1 mol 15.00 g BaCl2 ΔH 염화 바륨은 때때로 불꽃 놀이에서 사용되는데밝은 녹색을 나타내고, 물에 녹으면 열을 낸다.BaCl2(s) → Ba^2+(aq) + 2Cl^-(aq)a) 1몰의 BaCl2가 용액에서 침전될 때 ΔH는 얼마인가?b) 15.00 g의 BaCl2가 침전할 때 ΔH는 얼마인가? Barium chloride is sometimes used in fireworksto give a bright green color.It gives off heat when dissolved in water.BaCl2(s) → Ba^2+(aq) + 2Cl^-(aq)a) What is ΔH when one mol of BaCl2 .. 2024. 5. 28. C6H5COOH -3226.7 kJ/mol 1.9862 g 21.84℃ 25.67℃ C6H5COOH -3226.7 kJ/mol 1.9862 g 21.84℃ 25.67℃ The enthalpy of combustion of benzoic acid (C6H5COOH) is commonly used as the standard for calibrating constant-volume bomb calorimeters; its value has been accurately determined to be –3226.7 kJ/mol. When 1.9862 g benzoic acid are burned in a calorimeter, the temperature rises from 21.84℃ to 25.67℃. What is the heat capacity of the bomb? (A.. 2024. 4. 24. C6H12O6 4.117 g 19.65 kJ/℃ 3.134℃ mass percent C6H12O6 4.117 g 19.65 kJ/℃ 3.134℃ mass percentcalculate the percent by mass of the glucose in the sample A 4.117 g impure sample of glucose (C6H12O6) was burned in a constant-volume calorimeter having a heat capacity of 19.65 kJ/℃. If the rise in temperature is 3.134℃, calculate the percent by mass of the glucose in the sample. Assume that the impurities are unaffected by the combustion.. 2024. 4. 24. 50.0 g metal 100.0℃ 24.8℃ 50.0 g water 51.2℃ 50.0 g metal 100.0℃ 24.8℃ 50.0 g water 51.2℃ Suppose 50.0 g of water in the Styrofoam cup has an in initial temperature of 24.8℃. When a 50.0 g piece of metal at a temperature of 100.0℃ is added, the temperature of the water and metal rise to final temperature of 51.2℃. What is the specific heat of this metal object? (Specific heat of water is 4.184 J/g•℃) 열용량과 비열 q = C m Δt ( 참고 https://ywpop.t.. 2024. 4. 20. 2H2O2(l) ΔH = -196 kJ H2O2(l) 5.00 g 2H2O2(l) ΔH = -196 kJ H2O2(l) 5.00 g Hydrogen peroxide can decompose to water and oxygen by the reaction: 2H2O2(l) → 2H2O(l) + O2(g) ... ΔH = –196 kJ Calculate the quantity of heat released when 5.00 g of H2O2(l) decomposes at constant pressure. 2H2O2(l) → 2H2O(l) + O2(g) ... ΔH = –196 kJ 2몰 H2O2의 분해열이 –196 kJ 이므로, ΔH = –196 kJ / 2 mol = –98 kJ/mol ---> H2O2 1몰당 분해열 H2O2의 몰질량 = 34.01 g/mol 이므로, .. 2024. 4. 20. 75 kg 165 lb 555 ft Washington monument work kJ 25% energy 75 kg 165 lb 555 ft Washington monument work kJ 25% energy How much work is done when a person weighing 75 kg (165 lb) climbs the Washington monument. 555 ft high? How many kilojoules must be supplied to do this muscular work, assuming that 25% of the energy produced by the oxidation of food in the body can be converted into muscular mechanical work. 1 ft = 0.3048 m 이므로, ( 참고 https://ywpop.tisto.. 2024. 3. 30. 이전 1 2 3 4 ··· 40 다음 반응형