51 Results
Bond Enthalpies and Exothermic or Endothermic Reactions   
(Other (1))
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Internal Energy   
(Other (1))
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Thermochemistry   
(Other (1))
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Thermochemical Equations   
(Other (1))
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Bond Enthalpies   
(Other (1))
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Measuring the Enthalpy Change   
(Other (1))
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Solutions   
(Movie/Animation, Audio/Visual (9))
Reactions and demonstrations exploring the concepts of solutions.
Energy from Oxidation of Food   
(Movie/Animation, Audio/Visual (4))
Food undergoes rapid oxidation when placed in molten potassium chlorate.
Calorimeter   
(Movie/Animation, Audio/Visual (4))
A coffee-cup calorimeter is demonstrated.
Crystallization of Supersaturated Sodium Acetate   
(Movie/Animation, Audio/Visual (3))
A supersaturated solution of sodium acetate is poured onto one small sodium acetate crystal. Crystals form from the liquid immediately upon contact with the seed crystal. A thermometer shows that the crystallization process is exothermic. A chemical hot pack is shown as an example of a commercially available supersaturated solution.
Energy from Oxidation of Food (main)   
(Movie/Animation, Audio/Visual (3))
Food is added to liquid potassium chlorate, resulting in oxidation of the food.
Endothermic Reaction   
(Movie/Animation, Audio/Visual (3))
Solid barium hydroxide octahydrate (Ba(OH)2*8H2O) and ammonium thiocyanate (NH4SCN) are mixed in a beaker, which is then placed on a few drops of water on a small board. The reaction that occurs is highly endothermic.
Bromine   
(Movie/Animation, Audio/Visual (2))
Reactions and explosions involving bromine are demonstrated.
Heat Conduction by Diamond   
(Movie/Animation, Audio/Visual (2))
Diamond is shown to conduct heat better than aluminum.
Sulfuric Acid into Water and Ice   
(Movie/Animation, Audio/Visual (2))
When sulfuric acid is mixed with water the temperature rises. When sulfuric acid is added to ice, the temperature rises at first, but as the ice melts, the temperature falls.
Enthlapy-Thermodynamics   
(Movie/Animation, Audio/Visual (10))
Reactions and demonstrations the explore thermodynamic concepts.
Calorimeter, Coffee Cup (ChemPages Lab)   
(Instructional Material (1))
Calorimeter, Coffee Cup: this is a resource in the collection "ChemPages Laboratory Resources". A coffee cup calorimeter is a useful, simple device that can be used to measure the temperature change that accompanies a reaction. A Styrofoam cup is used because it is a good insulator. The cup will absorb (or supply) negligible amounts of heat during most General Chemistry experiments. Thus, any change in temperature is assumed to be due only to the reaction, and the heat transferred in the reaction may be calculated. The ChemPages Laboratory Resources are a set of web pages that include text, images, video, and self check questions. The topics included are those that are commonly encountered in the first-year chemistry laboratory. They have been put together for use as both a pre-laboratory preparation tool and an in-laboratory reference source.
Thermochemistry : CalcMolarEnthalpy (5 Variations)   
(Assessment Material (1))
White phosphorus, P4, ignites in air to produce heat, light, and P4O10 according to the following reaction.

P4(s) + 5O2(g) P4O10(s)

If 67.2 g of P4 is burned,1620 kJ of energy is evolved. What is the molar enthalpy of combustion of P4 if the process was carried out under constant pressure?

Intermolecular_Forces__Liquids_and_Solids : PhaseEnergyChanges (6 Variations)   
(Assessment Material (1))
When a liquid is transformed into its vapor at constant temperature,
Thermochemistry : PhaseChanges (8 Variations)   
(Assessment Material (1))
Steam at 100oC is condensed by an ice-water mixture at 0oC. Assuming that there is still ice present when the process is over, how much ice will be melted if 10.0 g of steam is condensed? The following may be useful:
enthalpy of vaporization of water = 40.7 kJ/mol; enthalpy of fusion of water = 6.07 kJ/mol; specific heat capacity of water = 4.184 J/g•K.
Thermochemistry : PhaseChangeEnthalpy (10 Variations)   
(Assessment Material (1))
A solid melts to a liquid. Which of the following statements are true? (Assume constant pressure and a flexible container.)
Thermochemistry : ConvertEnergyUnits (4 Variations)   
(Assessment Material (1))
The label on a granola bar says it provides 120 Calories. How many kilojoules of energy will this bar provide if it is completely metabolized?
Thermochemistry : MassFromCalorimetry (2 Variations)   
(Assessment Material (1))
The table below lists the specific heat capacities of several metals and liquids.

SubstanceSpecific Heat Capacity
J/(g.oC)
SubstanceSpecific Heat Capacity
J/(g.oC)
Al0.902H2O4.18
Fe0.451C2H5 OH2.46
Cu0.383CCl40.861
Au0.128CCl2F2 0.598

In an experiment a block of aluminum was heated to 100oC and placed in 200 g of water at 25oC. If the final temperature of the system is 43oC, and no heat transfer to the surroundings occurred, what is the mass of the aluminum block?

Thermochemistry : CalcHHessLaw (8 Variations)   
(Assessment Material (1))
The industrial process for making sulfuric acid has three steps. Using the data given, calculate the enthalpy change for the overall reaction for the process (the equation is given below).

2S(s) + 3O2(g) + 2H2O(l)2H2SO4(l)

Data:

S(s) + O2(g) SO2(g) Hrxn = -296.83 kJ
2SO3(g)O2(g) + 2SO2(g) Hrxn = -198.2 kJ
SO3(g) + H2O(l)H2SO4(l) Hrxn = -227.72 kJ

Thermochemistry : HeatCapacitySolLiq (4 Variations)   
(Assessment Material (1))
The Table below lists the specific heat capacities of several metals and liquids.

Substance Specific Heat Capacity
J/(g.oC)
Substance Specific Heat Capacity
J/(g.oC)
Al 0.902 H2O 4.18
Fe 0.451 C2H5OH 2.46
Cu 0.383 CCl4 0.861
Au 0.128 CCl2F2 0.598

In an experiment, 50 g of a metal was heated to 100oC and placed in 200 g of a liquid at 25oC. Which of the following combinations of metal and liquid will produce the largest temperature increase in the liquid? (Assume that there is no transfer of energy to the surroundings.)

Bonding : EnergyBreakAllBonds (10 Variations)   
(Assessment Material (1))
Use the bond energies given in to determine the total energy needed to break all of the bonds in C3H6. (Do not use ring structures.)
Thermochemistry : EnthalpyEnergy (10 Variations)   
(Assessment Material (1))
2SO2(g) + O2(g)2SO3(g)
Horxn = -197.78 kJ
How much energy is transferred when 96.6 g of SO2 reacts to form SO3?
Thermochemistry : CalcHCombustion (6 Variations)   
(Assessment Material (1))
Using the thermodynamic data given in , determine the enthalpy change for the combustion of ethane to produce carbon dioxide and water vapor.

2C2H6(g) + 7O2(g) 4CO2(g) + 6 H2O(g)

Thermochemistry : CalcHBondEnergy (14 Variations)   
(Assessment Material (1))
Use the bond energies given in to estimate the Ho for the reaction given below:

hint: both carbon dioxide and molecular oxygen have double bonds

Thermochemistry : HeatCapacityLiq (4 Variations)   
(Assessment Material (1))
100 g of water (c=4.184 J/g.oC), 100 g of ethanol (c=2.46 J/g.oC), 100 g of carbon tetrachloride (c=0.861 J/g.oC), and 100 g of ethylene glycol (c=2.42 J/g.oC) at 50oC were each placed into a separate coffee cup calorimeter and the temperature recorded. The temperature of the surroundings was 20oC. After one hour the temperature of which substance would have changed by the largest amount? Assume that the rate of heat transfer from the coffee cup to the surroundings was the same in each case.
Thermochemistry : HeatCapacityGraph (6 Variations)   
(Assessment Material (1))

Consider the graph above. Which of these substances has the highest specific heat capacity?

Thermochemistry : FuelAmpWattHeat (4 Variations)   
(Assessment Material (1))
Gasoline has an enthalpy of combustion of approximately 24000 kJ/gallon. When gasoline burns in an automobile engine, approximately 30% of the energy released is used to produce mechanical work. The remainder is lost as heat transfer to the engine's cooling system and eventually the atmosphere. As a start on estimating how much heat transfer is required, calculate what mass of water could be heated from 25 to 100oC by the combustion of 1.0 gallon of gasoline in an automobile.
Thermochemistry : CoffeeCupCalorimeter (2 Variations)   
(Assessment Material (1))
A block of copper is heated to {x} °C and then is dropped into a coffee cup calorimeter containing {y} g of water at 25.0 °C. The final temperature of the system is 45.1 °C. What is the mass of the copper block to the nearest gram? (Assume all heat is transferred to the water). Write your answer in the box, and do NOT include units.

Specific heat capacity of copper = 0.383 J/(g*°C)

Specific heat capacity of water = 4.18 J/(g*°C)

Thermochemistry : CalcHStateChange (4 Variations)   
(Assessment Material (1))
Calculate the enthalpy change when 100. g of ice at 0.0 oC is heated to liquid water at 50.0oC. (The heat of fusion for water is 333 J/g.)
Thermochemistry : BombCalorimeter (4 Variations)   
(Assessment Material (1))
Stearic acid (CH3(CH2)16CO2H) is a fatty acid, the part of fat that stores most of the energy. 1.00 g of stearic acid was burned in a bomb calorimeter. The bomb had a heat capacity of 652 J/oC and a 500. g water reservoir. If the temperature rose from 25.0 to 39.3 oC, how much heat was released when the stearic acid was burned?
Thermochemistry : HeatTransfers (10 Variations)   
(Assessment Material (1))
A red-hot piece of lead is dropped into water. Which of the following statements are true? (Assume that there are no energy transfers between anything except the lead and the water.)
Thermochemistry : ThermalEnergy (2 Variations)   
(Assessment Material (1))
The sketch below shows two identical flasks with different volumes of water at the same temperature. Which of the following is true?
Thermochemistry : GeneralEnergy (10 Variations)   
(Assessment Material (1))
Which of the following statements about energy is NOT true?
Thermochemistry : FlaskTemp (6 Variations)   
(Assessment Material (1))
If 200. J of thermal energy was added to both flasks, which of the following would happen?
Thermochemistry : BondEnergies (10 Variations)   
(Assessment Material (1))
Use to determine which of the following requires the most energy.
Thermochemistry : SystemSurrExoEndo (4 Variations)   
(Assessment Material (1))
Sulfuric acid is added to water in a beaker and the resulting solution is much warmer than either the water or acid was initially.
Identify the following items as being part of the system or the surroundings, and indicate whether the process is exothermic or endothermic.
Fat vs. Sugar Metabolism   
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A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Hess’ Law in Geology-Thermochemistry of Iron and its Ores   
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A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Weight of Food and Energy Production   
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A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Energy from Fats and Sugars   
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A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Thermochemical Equations in Geology-Serpentinization-The Heat Engine at Lost City   
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A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Measuring the Enthalpy Change Lecture Demonstrations   
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A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Enthalpy of Fusion and Enthalpy of Vaporization Lecture Demonstrations   
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A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Original Writings of Joseph Black on the Melting of Ice (ca. 1760)   
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A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Is E85 at $2.39 Better than Regular Gas at $2.79   
()
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
ChemPaths 104 F Mar 25   
()
Today in Chem 104: * Lecture: Thermochemistry * Reading: Kotz: Review Ch. 5, Sec. 1-8 Moore: Review Ch. 6, Sec. 1-10 * Homework #8 due by 11:55 PM F Apr 1 * Quiz in second discussion section next week