WorksheetsPhysical Chemistry (3.2)
Total questions: 31
Worksheet time: 20mins
What are the standard conditions?
298k
273k
100kPa
10kPa
What is TRUE for exothermic reactions?
Loses heat to its surroundings
Has negative enthalpy change
Products have a lower enthalpy
Always involves water
What is TRUE for endothermic reactions?
Enthalpy of products is greater than reactants
The system gains heat from surroundings
Has positive enthalpy change
Produces ice
The minimum energy required to start a reaction by breaking the bonds in the reactants.
(a)
For an endothermic enthalpy diagram, the reactants are (a) the products
For an exothermic enthalpy diagram, the reactants are (a) the products
What are standard conditions for enthalpy?
273K
298K
100kPa
1moldm-3
Convert 25 Celsius to Kelvin?
298k
273k
225K
289K
q = mc ΔT
What does q stand for and in what unit is it measured?
Heat exchanged to surroundings (Joules)
Heat exchanged to surroudnings (kilojoules)
Temperature change ( Celcius)
Temperature Change ( Kelvin)
q = mc ΔT
What does m stand for and in what unit is it measured?
Mass (Grams)
Mass (Kilograms)
Temperature change (Celcius)
Temperature Change ( Kelvin)
q = mc ΔT
What does c stand for and in what unit is it measured?
Mass (Grams)
Mass (Kilograms)
Specific Heat Capacity (Jg-1K-1)
Specific Latent Heat (Jg -1 K-1)
q = mc ΔT
What does ΔT stand for and in what unit is it measured?
Temperature Change (Celsius)
Temperature change (Kelvin)
Specific Heat Capacity (Jg-1K-1)
Specific Latent Heat (Jg -1 K-1)
What tells you how much energy is needed to break a bond?
Bond enthalpies
Melting points
Boiling points
Bond entropies
Breaking bonds is...
Endothermic
Exothermic
Making bonds is...
Endothermic
Exothermic
What factors affect the rate of reaction?
Temperature
Pressure
Concentration
Surface Area
Addition of a catalyst
What must always be included in an answer about the rate of reaction?
Collision theory
Size of the molecule
Proton Number
Formation equation
A substance that increases the rate of reaction without being used up during the process
(a)
A catalyst that is in the same state as its reactants
Homogenous catalyst
Heterogenous catalyst
Monogenous catalyst
Polygenous catalyst
A catalyst that is in a different state to its reactants
Homogenous catalyst
Heterogenous catalyst
Monogenous catalyst
Polygenous catalyst
What is the name for natural catalysts?
Enzymes
Hormones
Neurotransmitters
Red blood cells
In a Boltzmann distribution graph, Ea stands for?
(a)
What effect does increased temperature have on the peak of a curve in a Boltzmann distribution graph?
To the left
To the right
Up
Down
A catalyst will reduce the activation energy, so on a Boltzmann distribution graph, the Ea line would move...
To the left
To the right
A reaction is at equilibrium when...
the conc of reactants and products remains constant
the rate of the forward reaction is the same as the backwards reaction
the reaction has come to a halt
the solution remains a colourless clear
Factors that can affect equilibrium...
Temperature
Conc of reactants/products
Pressure in gaseous reactions
Presence of a catalyst
Who's principle is used for equillibrium?
Le Chatelier's
Boltzman
Hardy Weinberg
Mendeleev
What is true of the Harber process?
Produces ammonia
Has a nickel catalyst
At a high pressure
Uses carbon and hydrogen
Equilibrium constant Kc gives an indication of...
Position of equilibrium
Feasibility of equilibrium
Temperature of equilibrium
Rate of equilibrium
If the Kc value is greater than 1, what is favoured?
Reactants
Products
If the Kc value is smaller than 1, what is favoured?
Reactants
Products
