chem

Question 1

for a chemical reaction to occur, the reacting particles must collide with one another.

Answer 1

collision theory

Question 2

Nature of Reactants
Temperature
Concentration
Surface Area
Pressure (Gases Only)
Catalysts
Typically, covalently bonded substances take longer to react due to a greater number of bonds that need to be broken
To break more bonds, the particles reacting need more energy

Answer 2

factors affecting rates of chemical reactions

Question 3

A chemical reaction that releases heat. The potential energy of the REACTANTS is MORE than the PRODUCTS (negative heat of reaction - ΔH). There was a net loss of energy because all of the energy absorbed to form the activated complex has been released, plus the difference between the reactants and products.

Answer 3

exothermic

Question 4

A chemical reaction that absorbs heat. The potential energy of the PRODUCTS is more than the potential energy of the REACTANTS (positive heat of reaction - ΔH). There was a net gain of energy because more energy was absorbed to form the activated complex, than released.

Answer 4

endothermic

Question 5

a state in which the rate of the forward reaction equals the rate of the backward reaction. In other words, there is no net change in concentrations of reactants and products.

Answer 5

equilibirum

Question 6

if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium shifts to counteract the change to reestablish an equilibrium. If a chemical reaction is at equilibrium and experiences a change in pressure, temperature, or concentration of products or reactants, the equilibrium shifts in the opposite direction to offset the change.

catalysts have no effect on the equilibrium position

Answer 6

le chatelier’s principle

Question 7

The difference between the POTENTIAL ENERGY OF THE REACTANTS and the PRODUCTS (P.E. of products minus P.E. of reactants)

Answer 7

enthalpy

Question 8

This subtle property that matter possesses in terms of the way energy is dispersed in , is sometimes erroneously referred to as “randomness” or even “disorder” but these descriptions do not fit the state of energy as well as they seem to describe some of the often obvious results.,

the more of this, the more disordered molecules are in a container , measures the disorder of the system

Answer 8

entropy

Question 9

the value of its reaction quotient at chemical equilibrium,

Answer 9

equilibirum constant

Question 10

The amount of energy needed to form the activated complex from the reactants

Answer 10

activiation energy

Question 11

Temporary, intermediate product that may either break apart and reform the reactants or rearrange the atoms and form new products

Answer 11

activated complex

Question 12

Energy an object or particle has because of its motion (ex. reactants moving)

Answer 12

kinetic energy

Question 13

Energy due to position, composition or arrangement (ex. the energy stored in a bond)

Answer 13

potential energy

Question 14

which change affects both the rate and the activiation energy of a chemical reaction

Answer 14

addition of a catalyst

Question 15

if the pressure on gaseous reactants is increased, the rate of reaction is increased because ther e is an increase in

Answer 15

a greater number of collisions between reacting particles (decrease in volume?)

Question 16

As the number of effective collissions between the reactant particles in a chemical reaction decreases, the rate of reaction

Answer 16

decreases

Question 17

what is the equilibrium expression for 3A (g) + B (g) = 2C(g)

Answer 17

K= C2/A3 (B)

Question 18

a flask at 25 is partially filled with water and stoppered, after a period of time the water level remained constant, which relationship best explains this?

Answer 18

the rate of evaporation = rate of condensation

Question 19

in a reaction that has achieved equilibrium, the point of equilibirum is least likely to be shifted when

Answer 19

a catalyst is added

Question 20

in a gaseous system, temperature remaining constant, an increase in pressure will

Answer 20

increase the reaction rate

Question 21

the greatest amount of AB would be produced if the equilibrium constant of the reaction is = to

Answer 21

(biggest exponential number to the power of 10)

Question 22

2SO2 + O2 = 2SO3 + heat
which would increase by an increase in pressure and dectrease in temperature

Answer 22

SO3 only

Question 23

ex. of a phase equilibrium

Answer 23

Cl2 (g)–> <–Cl (l)

Question 24

which system at equilibrium will be least affected by a change in pressure

Answer 24

whichever equation does not have gas, (and aq solution) solids and liquids are not as affected

Question 25

H2(g) + Cl2(g) –> <– 2HCl (g) + heat , the equilibrium will shift to the right when there is an increase in

Answer 25

concentration of H2/Cl2

Question 26

A(g) + B (g) –><– C (g) + D(g), an increase in the concentration of A(g) would cause a decrease in

Answer 26

B(g), because the equilibirum is between A and D and B and C

Question 27

AgCl(s)–><–Ag+(aq) + Cl-(aq), when 0.1 M HCL is added to the system, the point of equilibrium will shift

Answer 27

to the left and the concentration of Ag+ (aq) will decrease

Question 28

A system is said to be in a state of dynamic equilibrium when

Answer 28

the rate at which products are formed is the same as the rate when reactants are formed

Question 29

in a reversible chemical reaction, which factors must be equal when the reaction is at equilibrium

Answer 29

rate at which reactants are formed and rate at which products are formed

Question 30

what is the enthalpy for an exothermic reaction

Answer 30

energy released, it is negative

Question 31

what is the enthalpy for an endothermic reaction

Answer 31

energy is absorbed, it is positive