Causes of Change Flashcards
Temperature and heat are different but related _________ properties.
physical
If a sample has a ________ temperature than its surrounding, energy is transferred from the sample.
higher
If the temperature of the sample is _______ than its surroundings, energy is transferred to the sample.
lower
The energy transferred between objects that are at different temperatures is ________
heat
The _____ of a sample is a measure of the average kinetic energy of the particles in a sample
temperature
The temperature of a sample does not depend on the amount of the sample, therefore temperature is a ___ property
intensive
In contrast, heat is a________ property, which means that the amount of energy transferred as heat depends on the amount of the sample.
extensive
The total energy content of a sample is its ______, and is represented by the symbol H.
enthalpy
The SI temperature unit is _____
Kelvin
A kelvin is the same temperature interval as a degree________
Celsius
What is energy?
The ability to do work or produce heat
What is potential energy?
the energy due to the composition or position of an object
What is kinetic energy?
Energy of motion
What is a calorie?
the amount of energy required to raise the temperature of 1 gram of pure water by one degree celsius
What is specific heat?
The amount of heat required to raise the temperature of 1 gram of that substance by one degree Celsius
What is thermochemistry?
The branch of science concerned with the energy(heat) changes that accompany chemical and phase changes
What is a system?
The specific part of the universe that contains the reaction or process
What is enthalpy?
the heat content of a system at constant pressure
What is molar enthalpy?
The energy change for 1 mole of a pure substance
What is a thermochemical equation?
A balanced chemical equation that includes the physical states of all reactants, products, and the energy change
What is calorimetry?
Used to measure the energy released or absorbed from a reaction by measuring a change in temperature of a standard liquid and setting the enthalpy equal to the reaction change
What is standard enthalpy (heat) of formation?
The enthalpy change in forming 1 mole of a substance from elements in their standard states
What is entropy?
A measure of the number of possible ways that the energy of a system can be distributed
What factors increase entropy?
When the particles’ freedom of movement increases, dissolving a solid, increasing the volume, increasing the energy, reducing the pressure
What is Gibbs Free Energy?
Energy that is available to do work
What would be the effect on the particles if more heat is supplied to the system?
They would speed up
The total energy of all the particles in a substance is called:
thermal energy
For a skillet, used for cooking, do you want a high or low specific heat
Low, so that it will change temperature quickly
If two objects have different temperatures when they come in contact, heat will flow from the warmer object to the cooler one UNTIL ____________
they both have an equal temperature
Calorimeters use insulating materials to:
prevent heat from escaping into the environment
What is the SI unit for energy?
Joule
Define exothermic reaction.
A chemical reaction that releases energy through heat or light
Entropy is:
disorder; delta S
If Delta G is small and positive,
The reverse reaction is spontaneous and the system is near equilibrium
T or F: The entropy of a gas increases with increasing temperatures.
True
What is 1 Calorie equal to?
1000 calories or 1kcal
A temperature difference taken between two objects has ______ numerical value in Kelvin and in degrees Celsius
the same
Heat is measured in :
joules
Kelvin temperature = celsius temperature + _________
273.15
The products of an _______ reaction have an energy higher than that of the reactants.
Endothermic
In endothermic reactions, delta H has a _______ value
positive
A chemical reaction occurs if it is accompanied by a(n) ________ in Gibbs energy.
decrease
According to the expression for delta G, the ________ the temperature for a positive entropy change, the greater the chances are that the reaction will be spontaneous.
higher
Free energy is zero at _______
equilibrium
The entropy of a substance _____ with temperature.
increases
____ have greater standard entropies than liquids
Gases
____ have the most freedom to move, so their standard entropies are the greatest
Gases
The property of a system that makes a process occur consists of two driving forces, a tendency toward the greatest _______ state and a tendency toward the lowest ____ state.
entropy, enthalpy
The quantity of entropy possessed by 1 mole of a substance is called ___
standard molar entropy
