Thermochemistry Fundamentals
The study of heat changes that occur during chemical reactions and physical changes.
What is thermochemistry?
The instrument used to measure the heat absorbed or released during a chemical or physical process.
What is a calorimeter?
Given the thermochemical equation SO2(g)+21O2(g)→SO3(g)ΔH=−99.1 kJ/mol, calculate the heat evolved when 74.6 g of sulfur dioxide (molar mass = 64.07 g/mol) is converted to sulfur trioxide.
What is -115.3 kJ?
Given the combustion reaction: CH4(g)+2O2(g)→CO2(g)+2H2O(g) and the ΔHc∘ values: CH4(g)=−890 kJ/mol, CO2(g)=−393.5 kJ/mol, H2O(g)=−242 kJ/mol. Calculate the enthalpy change of the reaction
What is -890 kJ?
The amount of heat required to change one mole of a liquid to a gas at constant temperature and pressure.
What is heat of vaporization?
In thermochemistry, this refers to the specific part of the universe being studied, such as the reactants and products in a reaction.
What is the system?
Calculate the heat in joules required to raise the temperature of 100.0 g of iron from 20.0°C to 100.0°C (Specific heat of iron = 0.449 J/g°C)
What is 3592 J?
For the reaction C2H5OH+3O2→2CO2+3H2OΔH=−1366.7 kJ, calculate the ΔH when 2 moles of ethanol (C2H5OH) react with excess oxygen
What is -2733.4 kJ?
Calculate the enthalpy change for the reaction: C3H8(g)+5O2(g)→3CO2(g)+4H2O(g) using the provided enthalpies of combustion: C3H8(g)=−2220 kJ/mol, CO2(g)=−393.5 kJ/mol, H2O(g)=−286 kJ/mol.
What is -104.5 kJ?
The amount of heat required to change one mole of a solid to a liquid at constant temperature and pressure.
What is heat of fusion?
A chemical reaction that releases heat energy to its surroundings, causing the temperature of the surroundings to increase.
What is an exothermic reaction?
If 150.0 g of water cools from 80.0°C and has 31,380 Joules of heat is released (meaning the water lost this much heat), calculate its final temperature. (Specific heat of water = 4.18 J/g°C).
What is 30.0°C?
For the reaction 4Fe(s)+3O2(g)→2Fe2O3(s)ΔH=−1500 kJ, if there is 1 mole of oxygen, calculate the ΔH for the reaction.
What is -500 kJ?
Find the enthalpy of the reaction: C6H12O6(s)+6O2(g)→6CO2(g)+6H2O(l) using the enthalpies of combustion below: C6H12O6(s)=−2808 kJ/mol, CO2(g)=−393.5 kJ/mol, H2O(l)=−286 kJ/mol.
What is -2808 kJ?
How many kilojoules of energy are in 2000 calories (1 cal = 4.184 J)?
What is 8.368 kJ? (Calculation: 2000 cal×4.184 J/cal=8368 J=8.368 kJ)
The heat content of a system at constant pressure, often represented by the symbol.
What is enthalpy?
A 500.0 g sample of water absorbed 100.0 kJ of energy. Calculate the change in temperature of the water (Specific heat of water = 4.18 J/g°C).
What is 47.8°C?
How many kJ of heat will be released when 4.72 g of carbon (Molar Mass = 12.01 g/mol) react with excess oxygen gas to produce carbon dioxide according to C+O2→CO2ΔH∘=−393.5 kJ?
What is -154.6 kJ?
How many kJ of heat will be released when 4.72 g of carbon (Molar Mass = 12.01 g/mol) react with excess oxygen gas to produce carbon dioxide according to C+O2→CO2ΔH∘=−393.5 kJ?
What is -154.6 kJ?
How many Calories (kilocalories) are equivalent to 2092 Joules (1 Cal = 4184 J)?
What is 0.500 Cal? (Calculation: 2092 J/4184 J/Cal=0.500 Cal)
The amount of heat required to raise the temperature of one gram of a substance by one degree Celsius (or Kelvin).
What is specific heat?
A 75.0 g piece of copper at 120.0 °C is placed in 200.0 g of water at 25.0 °C. If the final temperature is 28.4 °C, calculate the specific heat of copper(Specific heat of water = 4.18 J/g°C).
What is 0.385 J/g°C?
For the reaction O2+2H2+22.0 kJ→2H2O, calculate the amount of heat absorbed if 5.0 mol of O2 reacts.
What is 110 kJ?
A 2.0 mol sample of methane is combusted. How much heat is released? (Methane ΔHcomb∘=−891 kJ/mol)
What is -1782 kJ?
The sign of ΔH for a process where heat is released to the surroundings.
What is negative?