Thermochemistry 1/14 Flashcards
What is thermochemistry?
Thermochemistry is the study of the heat energy involved in chemical reactions and changes of state.
What is the unit of heat in the metric system?
The unit of heat in the metric system is the joule (J).
True or False: A calorie is defined as the amount of heat needed to raise the temperature of 1 gram of water by 1 degree Celsius.
True.
How many joules are in one calorie?
One calorie is approximately 4.184 joules.
What is specific heat capacity?
Specific heat capacity is the amount of heat required to raise the temperature of 1 kilogram of a substance by 1 degree Celsius.
Fill in the blank: The formula for calculating heat (q) is q = _____ x m x ΔT.
c
What does the symbol ΔT represent in thermochemical equations?
ΔT represents the change in temperature.
What is the specific heat capacity of water?
The specific heat capacity of water is approximately 4.18 J/g°C.
True or False: The heat capacity of a substance depends on the amount of substance present.
True.
What is the difference between heat and temperature?
Heat is the energy transferred between substances, while temperature is a measure of the average kinetic energy of the particles in a substance.
What is the equation for calculating the heat absorbed or released during a phase change?
q = n * ΔH, where n is the number of moles and ΔH is the enthalpy of the phase change.
Fill in the blank: The enthalpy change associated with a chemical reaction at constant pressure is represented by _____ (ΔH).
enthalpy change
What is the calorimeter used for?
A calorimeter is used to measure the heat of chemical reactions or physical changes.
What is the heat of reaction?
The heat of reaction is the amount of heat released or absorbed during a chemical reaction.
True or False: Thermochemistry only deals with exothermic reactions.
False.
What does the term ‘exothermic’ mean?
Exothermic refers to a reaction that releases heat to the surroundings.
What does the term ‘endothermic’ mean?
Endothermic refers to a reaction that absorbs heat from the surroundings.
What is the standard heat of formation?
The standard heat of formation is the change in enthalpy when one mole of a compound is formed from its elements in their standard states.
Fill in the blank: The law of conservation of energy states that energy cannot be _____ or _____; it can only be transformed from one form to another.
created, destroyed
What is the equation for calculating work done by a gas during expansion?
W = -PΔV, where W is work, P is pressure, and ΔV is the change in volume.
What is the significance of the Gibbs free energy?
Gibbs free energy determines the spontaneity of a process; a negative Gibbs free energy indicates a spontaneous process.
What is the heat capacity at constant volume represented by?
The heat capacity at constant volume is represented by Cv.
What is the heat capacity at constant pressure represented by?
The heat capacity at constant pressure is represented by Cp.
True or False: Heat capacity is an extensive property.
True.
