In a calorimeter, the energy content of a substance is calculated from measurement of the temperature change in a known mass of what?
Water
Energy absorbed or released as heat in a chemical or physical change is measured by?
Calorimeter
The energy transferred between samples of matter because of a difference in their temperature is called?
Heat
What is energy in the form of heat described as?
The energy transferred between samples of matter because of a difference in their temperatures.
What is the energy required to raise the temperature of 1 g of a substance by 1 C or 1 K?
Specific Heat
The q in thermodynamic equations is?
Energy lost or gained.
For exothermic reaction, the products at a lower or higher energy level than the reactants?
Lower.
What is ice melting an example of?
A negative entropic reactions
What enthalpy change favors a spontaneous reaction?
A Large negative change.
What do collisions require to be effective?
Enough Energy and a favorable orientation
What do colliding molecules have when they have an orientation that favors reaction?
The correct angles and distances between atoms
When you raise the temperature of gas particles what are you doing to the collision energy and to the favorability of orientation?
Increasing collision energy and not increasing favorability of orientation.
What is the minimum energy required for an effective collision called?
Activation energy
When bonds break, are they exothermic or endothermic?
Endothermic
^H is positive for endothermic or exothermic?
Endothermic
What us true in an exothermic reaction?
Energy of products<energy of reactants<activation energy
What is the measure of a decrease in reactant concentration per unit time in a reaction?
Reaction Rate
Is the reaction rate higher or lower of the concentration of reactants is higher?
Higher
What happens to the enthalpy in a chemical reaction in terms of its products and reactants?
The enthalpy change for a reaction equals the total enthalpy of the products minus the total enthalpy of the reactants.
What are the two factors that determine whether a molecule collision produces a reaction?
Sufficient energy and orientated correctly towards each other.
What factors influence the rate of a chemical reaction?
Temperature, surface area, concentration, pressure, nature of each reactant, and the presence of catalyst or inhibitor.
What does the average kinetic energy equal?
Temperature
What is the quantity of energy released or absorbed as heat during a chemical reaction?
Enthalpy of Reaction
What provides an alternate pathway with a lower activation energy?
Catalyst
What equation is an exothermic equation?
2 C8H18 + 25 O2 16 CO2 + 18 H2O + E
or
2H2O 2H2 + O2 ?H = 53kJ
What phase changes require energy?
Solid to a gas, liquid to a gas, or solid to a liquid
What increases in concentration as the reaction proceeds?
Products
What is the enthalpy if the reaction is endothermic?
Positive
What is the enthalpy if the reaction is exothermic?
Negative
In order for a reaction to occur, what must the reactants do?
Collide with correct orientation and with enough force.