Consider a balloon filled with 2115 L of helium at 1.00 atm pressure and 45.5°C. The temperature of the balloon is decreased to 11.7°C with the pressure remaining at 1.00 atm. What is AE (in kJ) for this change? (Assume ideal conditions. The molar heat capacity for He at constant pressure, Cp, is 20.8 J/°C•mol.)

When a 4.31 g sample of liquid octane (C8H18) is burned in a bomb calorimeter, the temperature of the calorimeter rises by 27.3 °C. The heat capacity of the calorimeter, measured in a separate experiment, is 6.2 kJ/•C. The calorimeter also contains 3.00 kg of water, specific heat capacity of 4.18 J/g°C. Determine the heat of combustion of octane in units of kJ/mol octane. Enter your answer numerically and in terms of kJ/mol.

the molar heat capacity of iron is 25.10 J mol –1 K–1 . A 25.0 g ball is heated until it is glowing red (to a temperature of 400.°C). It is dropped into a 50.0 mL container of water at 25.0°C. If the density of water is 0.997 g mL–1 , and the molar heat capacity of water is 4.186 J g–1 K–1 , what temperature (in K) will the ball and water equilibrate to? A) 338 B) 300 C) 317 D) 359 E) 342

A student runs two experiments with a constant-volume "bomb" calorimeter containing 1400. g of water (see sketch at right). First, a 5.000 g tablet of benzoic acid (CH-CO₂H) is put into the "bomb" and burned completely in an excess of oxygen. (Benzoic acid is known to have a heat of combustion of 26.454 kJ/g.) The temperature of the water is observed to rise from 21.00 °C to 42.00 °C over a time of 8.5 minutes. Next, 5.190 g of ethylene (C₂H4) are put into the "bomb" and similarly completely burned in an excess of oxygen. This time the temperature of the water rises from 21.00 °C to 63.35 °C. Use this information, and any other information you need from the ALEKS Data resource, to answer the questions below about this reaction: Is this reaction exothermic, endothermic, or neither? If you said the reaction was exothermic or endothermic, calculate the amount of heat that was released or absorbed by the reaction in the second experiment. exothermic C₂H₂(g) + 30₂(g) → 2CO₂(g) + 2H₂O(g) Be…

Calculate the energy required (in units of kJ) to heat 12.00 g water from 22.00 oC to 115.0 oC? Specific heat capacity for liquid water is 4.184 J/(g·oC), the heat capacity for water vapor is 2.000 J/(g·oC).  The heat of vaporization for water in the gaseous state is 2260.0 J/g.

A student runs two experiments with a constant-volume "bomb" calorimeter containing 1300. g of water (see sketch at right). First, a 5.000 g tablet of benzoic acid (CH-CO₂H) is put into the "bomb" and burned completely in an excess of oxygen. (Benzoic acid is known to have a heat of combustion of 26.454 kJ/g.) The temperature of the water is observed to rise from 22.00 °C to 42.76 °C over a time of 9.6 minutes. Next, 5.990 g of ethane (C₂H) are put into the "bomb" and similarly completely burned in an excess of oxygen. This time the temperature of the water rises from 22.00 °C to 71.14 °C. Use this information, and any other information you need from the ALEKS Data resource, to answer the questions below about this reaction: Is this reaction exothermic, endothermic, or neither? If you said the reaction was exothermic or endothermic, calculate the amount of heat that was released or absorbed by the reaction in the second experiment. Calculate the reaction enthalpy ΔΗ per mole of C₂H6.…

A student runs two experiments with a constant-volume "bomb" calorimeter containing 1500. g of water (see sketch at right). First, a 6.500 g tablet of benzoic acid (CH₂CO₂H) is put into the "bomb" and burned completely in an excess of oxygen. (Benzoic acid is known to have a heat of combustion of 26.454 kJ/g.) The temperature of the water is observed to rise from 18.00 °C to 44.66 °C over a time of 14.6 minutes. Next, 4.910 g of ethanol (C₂H5OH) are put into the "bomb" and similarly completely burned in an excess of oxygen. This time the temperature of the water rises from 18.00 °C to 40.44 °C. Use this information, and any other information you need from the ALEKS Data resource, to answer the questions below about this reaction: Is this reaction exothermic, endothermic, or neither? If you said the reaction was exothermic or endothermic, calculate the amount of heat that was released or absorbed by the reaction in the second experiment. Calculate the reaction enthalpy AHxn per mole of…

Consider a balloon filled with 2115 L of helium at 1.00 atm pressure and 45.5°C. The temperature of the balloon is decreased to 26.3°C with the pressure remaining at 1.00 atm. What is ∆E (in kJ) for this change? (Assume ideal conditions. The molar heat capacity for He at constant pressure, Cp, is 20.8 J/°C･mol.)

A student runs two experiments with a constant-volume "bomb" calorimeter containing 1200. g of water (see sketch at right). First, a 7.500 g tablet of benzoic acid (CH₂CO₂H) is put into the "bomb" and burned completely in an excess of oxygen. (Benzoic acid is known to have a heat of combustion of 26.454 kJ/g.) The temperature of the water is observed to rise from 18.00 °C to 51.74 °C over a time of 14.9 minutes. Next, 4.510 g of ethane (C₂H₂) are put into the "bomb" and similarly completely burned in an excess of oxygen. This time the temperature of the water rises from 18.00 °C to 53.35 °C. Use this information, and any other information you need from the ALEKS Data resource, to answer the questions below about this reaction: Is this reaction exothermic, endothermic, or neither? If you said the reaction was exothermic or endothermic, calculate the amount of heat that was released or absorbed by the reaction in the second experiment. Calculate the reaction enthalpy ΔΗ per mole of C₂H6.…

The molar heat capacity of silver is 25.35 J/mol · °C. How much energy would it take to raise the temperature of 9.90 g of silver by 15.0 °C? Express your answer with the appropriate units.