Chemistry Chapter 17
specific heat capacity
Amount of heat required to raise the temperature of 1 gram of substance 1 °C symbol- C unit- J/g x c
∆Hvap
Heat of vaporization which is heat required to change 1g of liquid to gas. Q= m x _____
the forward and reverse reactions are proceeding at the same rate
In a state of chemical equilibrium,
reverse reaction is favored
Keq<1
neither reaction is favored
Keq=1
forward reaction is favored
Keq>1
specific heat
Q=mXCX∆t What is C?
mass (grams)
Q=mXCX∆t What is m?
change in temperature
Q=mXCX∆t What is ∆t?
heat absorbed
Q=mXCX∆t what is Q?
phase diagram
a graph of pressure versus temperature that shows in which phase a substance exists under different conditions of temperature and pressure.
temperature
a measure of the average kinetic energy of the particles in a sample of matter. It doesn't depend on the amount of water in the sample. symbol-t unit is °C
reversible reaction
a reaction in which the product can react to form the reactant
activated complex
a short-lived, unstable arrangement of atoms that can break apart and reform the reactants or can form products; also sometimes referred to as the transition state.
catalyst
a substance that changes the rate of the reaction without being permanently altered
enzymes
act as catalysts in our body
no shift in equilibrium
addition of a catalyst, the system will shift....
away from added chemical
additionl of a chemical, the system will shift....
toward the side with the greater number of gas particles
decrease in pressure, the system will shift....
toward the source of energy
decrease in temperature, the system will shift....
Kinetic energy
energy in motion
endothermic
exothermic or endothermic? Kinetic energy is converted into potential energy
exothermic
exothermic or endothermic? combustion
endothermic
exothermic or endothermic? evaporation
endothermic
exothermic or endothermic? heat seems to disappear
exothermic
exothermic or endothermic? products are more stable than reactants
nature of the reactant, concentration of the reactants, temperature, catalyst, and surface area
factors affecting the reaction rate
∆Hfus
heat of fusion which is heat required to change 1g of solid to liquid. Q= m x _____
The enzymes lower the required energy for an effective collision
how is it possible for body sugars to burn inside your body at a normal body temperature?
toward the side with the smaller number of gas particles
increase in pressure, the system will shift....
away from the source of energy
increase in temperature, the system will shift....
lowering the amount of the energy to achieve effective collision
increase the rate of reaction by....
temperature of the reactant
increasing temperature of a reactant causes a more effective collision which increases the rate of the reaction
concentration of the reactants
increasing the concentration of reactants leads to more effective collisions, which leads to an increased rate of reaction
increase the concentration of reactants which increases effective collision
increasing the pressure of the reactants (gas only)....
surface area of reactants
increasing the surface area causes a more effective collision which also increases the rate of the reaction
or is oxidized at normal body temperature, which is 37*C
inside our body sugar burns.......
Double arrows
means the equation is reversible
activation energy
minimum amount of energy required by reacting particles in order to form the activated complex and lead to a reaction.
only when temperatures are above 600*C
outside the body sugar burns......
collision theory
particles must first collide in an effective collision and the particles must collide with the correct orientation and the proper amount of energy.
endothermic
physical or chemical change in which a system absorbs heat from its surroundings. example- melting KE-> PE
exothermic
physical or chemical change in which system gives off heat to its surroundings. PE-> KE
toward the removed chemical
removal of a chemical, the system will shift....
brackets around a formula
represent concentration
Le Chatelier's Principle
states that when a stress is applied to a system in equilibrium, the system reacts to reduce the stress
potential energy
stored energy. Potential energy can't be measured, only the change of potential energy can be measured
reaction rates
the rate at which the reactants disappear and the products appear
systems and surroundings
the specific part of the universe containing the reaction or process being studied. Includes everything in the universe except the system.
nature of the reactants
the stability of the reactants, type of bonds involved, and the states of matter
chemical kinetics
the study of reaction rates
if the volume is decreased, the gas molecules are closer together and have a greater chance of making an effective collision
use the collision theory to explain: a mixture of hydrogen gas and chlorine gas reacts faster when the volume they occupy is decreased.
An increase in temperature causes the particles to move faster increasing the chance of an effective collision
use the collision theory to explain: an increase in temperature increases the reaction rate
Iron filings have a greater surface area than the nail, and this exposes a greater area of contact between the reactant
use the collision theory to explain: iron filings rust faster than iron wire
Reaction rates will determine how quickly products are formed. The faster products are formed, the higher the profit
use the collision theory to explain: why do you think that industrial chemists are concerned with reaction rates
rate
what is equal in a state of equilibrium?
product decreases and the reactants increase
when an equilibrium system shifts to the left....
product increases and the reactants decrease
when an equilibrium system shifts to the right....