Multiple ChoiceWhen water evaporates from a beaker at 25℃, 44.0 kJ/mol of heat is required. How much heat is required when 10.0 g of water completely evaporates? H2O (l) → H2O (g); ΔH = +44.0 kJ/mol400views
Textbook QuestionA 1.50-g sample of quinone 1C6H4O22 is burned in a bomb calorimeter whose total heat capacity is 8.500 kJ>°C. The temperature of the calorimeter increases from 25.00 to 29.49°C. (b) What is the heat of combustion per gram of quinone and per mole of quinone?1437views
Textbook QuestionDetermine whether each process is exothermic or endothermic and indicate the sign of ΔH. a. dry ice evaporating b. a sparkler burning c. the reaction that occurs in a chemical cold pack used to ice athletic injuries574views
Textbook QuestionA 2.20-g sample of phenol 1C6H5OH2 was burned in a bomb calorimeter whose total heat capacity is 11.90 kJ>°C. The temperature of the calorimeter plus contents increased from 21.50 to 27.50 °C. (b) What is the heat of combustion per mole of phenol?774views
Textbook QuestionUnder constant-volume conditions, the heat of combustion of benzoic acid (C6H5O6) is 15.57 kJ/g. A 3.500-g sample of sucrose is burned in a bomb calorimeter. The temperature of the calorimeter increases from 20.94 to 24.72 °C. (b) If the size of the sucrose sample had been exactly twice as large, what would the temperature change of the calorimeter have been?1034views
Textbook QuestionUnder constant-volume conditions, the heat of combustion of benzoic acid (C6H5O6) is 15.57 kJ/g. A 3.500-g sample of sucrose is burned in a bomb calorimeter. The temperature of the calorimeter increases from 20.94 to 24.72 °C. (a) What is the total heat capacity of the calorimeter?1932views
Textbook QuestionUnder constant-volume conditions, the heat of combustion of naphthalene 1C10H82 is 40.18 kJ>g. A 2.50-g sample of naphthalene is burned in a bomb calorimeter. The temperature of the calorimeter increases from 21.50 to 28.83 °C. (c) Suppose that in changing samples, a portion of the water in the calorimeter were lost. In what way, if any, would this change the heat capacity of the calorimeter?1158views
Textbook QuestionExactly 1.5 g of a fuel burns under conditions of constant pressure and then again under conditions of constant volume. In measurement A the reaction produces 25.9 kJ of heat, and in measurement B the reaction produces 23.3 kJ of heat. Which measurement (A or B) corresponds to conditions of constant pressure? Explain.1432views
Textbook QuestionWhen 0.514 g of biphenyl (C12H10) undergoes combustion in a bomb calorimeter, the temperature rises from 25.8 °C to 29.4 °C. Find ΔErxn for the combustion of biphenyl in kJ>mol biphenyl. The heat capacity of the bomb calorimeter, determined in a separate experiment, is 5.86 kJ/°C.4659views3rank
Textbook QuestionMothballs are composed primarily of the hydrocarbon naphthalene (C10H8). When 1.025 g of naphthalene burns in a bomb calorimeter, the temperature rises from 24.25 °C to 32.33 °C. Find ΔErxn for the combustion of naphthalene. The heat capacity of the bomb calorimeter, determined in a separate experiment, is 5.11 kJ/°C.3973views
Textbook QuestionDoes a measurement carried out in a bomb calorimeter give a value for ∆H or ∆E? Explain.648views
Textbook QuestionWhen 0.187 g of benzene, C6H6, is burned in a bomb calorimeter the temperature rises by 3.45 °C. If the heat capacity of the calorimeter is 2.46 kJ>°C, calculate the combustion energy 1∆E2 for benzene in units of kJ/g and kJ/mol.1131views
Textbook QuestionThe heat of combustion of fructose, C6H12O6, is -2812 kJ>mol. If a fresh golden delicious apple weighing 120 g contains 16.0 g of fructose, what caloric content does the fructose contribute to the apple?1484views
Textbook QuestionThe heat of combustion of ethanol, C2H5OH(l), is -1367 kJ>mol. A bottle of stout (dark beer) contains up to 6.0% ethanol by mass. Assuming the density of the beer to be 1.0 g>mL, what is the caloric content due to the alcohol (ethanol) in a bottle of beer (500 mL)?4679views
Textbook QuestionPalmitic acid (C16H32O2) is a dietary fat found in beef and butter. The caloric content of palmitic acid is typical of fats in general. Write a balanced equation for the complete combustion of palmitic acid and calculate the standard enthalpy of combustion. What is the caloric content of palmitic acid in Cal/g? The standard enthalpy of formation of palmitic acid is -208 kJ/mol and that of sucrose is -2226.1 kJ>mol. [Use H2O(l ) in the balanced chemical equations because the metabolism of these compounds produces liquid water.]1892views
Textbook Question(b) Assuming that there is an uncertainty of 0.002 °C in each temperature reading and that the masses of samples are measured to 0.001 g, what is the estimated uncertainty in the value calculated for the heat of combustion per mole of caffeine?893views
Textbook QuestionFrom the following data for three prospective fuels, calculate which could provide the most energy per unit mass and per unit volume: Fuel Density at 101.3 kPa (g/cm3) Molar Enthalpyof Combustion (MJ/mol) Octane, C8H181l2 0.70 at 20 °C -5.53 Liquid Butane, C4H101l2 0.60 at -1 °C -2.88 Liquid hydrogen, H21l2 0.07 at -253 °C -0.29559views
Open QuestionA sample of 0.562 g of carbon is burned in oxygen in a bomb calorimeter, producing carbon dioxide. assume both the reactants and products are under standard state conditions, and that the heat released is directly proportional to the enthalpy of combustion of graphite. The temperature of the calorimeter increases from 26.74 °C to 27.93 °C. What is the heat capacity of the calorimeter and its contents?166views
Open QuestionWhen a 0.740-g sample of trinitrotoluene (tnt), C7H5N2O6, is burned in a bomb calorimeter, the temperature increases from 23.4 °C to 26.9 °C. The heat capacity of the calorimeter is 534 J/°C, and it contains 675 ml of water. How much heat was produced by the combustion of the tnt sample?201views
Open QuestionCalculate the heat capacity of a calorimeter if the combustion of 5.000g of benzoic acid212views
Open QuestionCalculate the heat capacity of the calorimeter if the combustion of 5.000g of benzoic acid155views
Open QuestionCompare the calorimeter that you built to a bomb calorimeter. How are they similar and different?162views