The Atmosphere Salters B Chemistry

Front 1

What must particles do to react?

Back 1

They must collide in the right direction (facing the right way) and must collide with a minimum amount of Kinetic energy.

Hint 1

Front 2

What is activation enthalpy?

Back 2

The minimum amount of kinetic energy needed for particles to react.(The particles need energy to break the bonds at the start of a reaction)

Hint 2

Activation Energy

Front 3

Why is an Enthalpy Profile Diagram shaped like this?

Back 3

because the reactants need enough energy for the bonds to break (Activation Enthalpy) and then the new bonds formed release energy.

Hint 3

Front 4

What does a Maxwell-Boltzmann distribution show?

Back 4

the number of molecules in a gas with different kinetic energies

Hint 4

Front 5

What happens of you increase the temperature of a reaction?

Back 5

Particles on average will have a higher kinetic energy and will move faster so a greater proportion of molecules will have the activation energy and will be able to react.
Also they will be moving faster so they'll collide more often.

Hint 5

zoom zoom

Front 6

How does increasing the temperature affect the shape of the Maxwell-Boltzmann distribution curve?

Back 6

It pushes to the right

Hint 6

Same amount of molecules so same area

Front 7

Apart from temperature what else speeds up the rate of reaction?

Back 7

Increasing the concentration
Increasing pressure
Increasing surface area
Addition of a catalyst

Hint 7

4 things

Front 8

How does increasing the concentration of the reactants speed up a reaction?

Back 8

Increasing the concentration of the reactants in a solution means the particles are closer together on average. If they're closer, they'll collide for often. So more collisions means more chances to react. Also more molecules means more molecules on average with high enough activation energy.

Front 9

How does increasing the surface area speed up a reaction?

Back 9

If the reactants are in a big lump then most of the particles won't collide with other reactants. However if they are in smaller lumps you will have a larger surface area to volume ration so more particles will come in contact with the other reactants.

Hint 9

surface to volume ratio

Front 10

How does adding a catalyst speed up a reaction?

Back 10

They lower the activation enthalpy by providing a different way for the bonds to be broken and remade. If the activation enthalpy is lower, more particles will have enough enthalpy to react.

Front 11

What is a homogeneous catalyst?

Back 11

A homogeneous catalyst is one which is in the same state as the reactants.

Hint 11

phases

Front 12

How do homogeneous catalysts work?

Back 12

A homogeneous catalyst speeds up reactions by forming one or more intermediate compounds with the reactants. The products are then formed from the intermediate compounds.

Front 13

How does having intermediate compounds speed up a reaction?

Back 13

The activation energy needed to form the intermediates (and to form the products from the intermediates) is lower than that needed to make the products directly from the reactants.

Hint 13

double bump

Front 14

What is the shape of an energy profile of a homogeneous catalyst reaction?

Back 14

Front 15

Why are there two bumps on the Enthalpy Profile of a homogeneous Catalyst Reaction?

Back 15

because there are intermediate bonds that which need to be formed

Hint 15

Front 16

What do Reversible Reactions reach?

Back 16

Dynamic Equilibrium

Hint 16

reactions that can work in both ways

Front 17

How is dynamic equilibrium reached?

Back 17

As the reactants get used up, the forward reaction slows down- as more product it formed the reverse reaction speeds up. After a bit the forward and backwards reactions will be going at the same rate.( the amounts of reactants and products will not change)

Front 18

What must the reaction happen in for it to reach Dynamic equilibrium?

Back 18

can only happen in a closed system

Front 19

What does Le Chatelier's Principle state?

Back 19

If there is a change in concentration, pressure or temperature, the equilibrium will move to help counteract the change.

Front 20

How do catalysts alter the position of equilibrium?

Back 20

They dont

Front 21

How does changing the concentration alter the equilibrium?

Back 21

•If you INCREASE the concentration of REACTANTS the equilibrium tries to get rid of the extra reactants and does this by making more product. So the equilibrium shifts to the RIGHT
•Increasing the concentration of the product the equilibrium tries to remove extra product so the reverse reaction will go faster. so equilibrium shifts to the LEFT

Front 22

How does altering the pressure effect equilibrium?

Back 22

•Increasing the pressure shifts equilibrium to the side with the fewest gas moles to reduce the pressure.
•Decreasing the pressure shifts the equilibrium to the side with the most bass molecules to increase the pressure.

Hint 22

moly mole

Front 23

How does altering the temperature effect equilibrium?

Back 23

•Increasing the temperature (adding heat) will cause the equilibrium to shift in the endothermic (positive ∆H) direction to absorb this heat.
•Decreasing the temperature (removal of heat) causes the equilibrium to shift in the endothermic (negative ∆H) direction to try and replace the heat

Hint 23

If the forward reaction is endothermic then the reverse will be exothermic.

Front 24

What is the percentages of different gasses in the lower atmosphere?

Back 24

78% - Nitrogen
21% - Oxygen
1% - Argon
0.035% - Carbon Dioxide
(varying amounts of water vapor and other gases in tiny amounts)

Hint 24

It comes out to over 100% as the figures have been rounded off slightly.

Front 25

What does ppm stand for?
and what is it used for?

Back 25

Parts Per Million
Is a measure used when talking about really small percentages of gas in the atmosphere.
eg Xenon = 0.000009% of the atmosphere which is 0.9 ppm .

Hint 25

not penguin party manifesto!

Front 26

Name the EM radiation in order from lowest energy to highest energy?

Back 26

Radio waves, Micro-waves, Infrared, Viable light, Ultra-violet, X-rays and Gamma rays

Hint 26

Ruth meddles in very unusual eXpeditions galore! :'( that is so bad

Front 27

What EM radiation does the sun (main 3) give out and why does it give out radiation?

Back 27

Infrared, Visible light, Ultraviolet
because of the nuclear processes going on in its core

Hint 27

is very Unhelpful

Front 28

How does UV/visible light effect molecules?

Back 28

Electrons get excited to higher energy levels. Bonds may be broken. (free radicals may be formed)

Hint 28

Poof

Front 29

How does Infrared radiation effect molecules?

Back 29

The BONDS in the molecules absorb energy and vibrate more.

Hint 29

shake shake shake señora

Front 30

How do microwaves effect molecules?

Back 30

The molecules absorb energy and rotate more

Hint 30

Literally a microwave!

Front 31

How do radio waves effect molecules?

Back 31

The molecule absorbs energy and translates more (moves faster)

Hint 31

Voom voom

Front 32

What effects the frequency of the vibrations of molecules?

Back 32

The strength of the bond
The mass of the atom

Front 33

What are free radicals?

Back 33

Atoms with unpaired electrons that are usually highly reactive so consequentially have a very short half life.

Hint 33

•••••••••

Front 34

Describe the greenhouse effect?

Back 34

The sun emits UV, IR and visible light. The radiation from reaches the earths atmosphere most of the UV and IR is absorbed by the atmospheric gasses, while some is reflected back in to space by clouds.
Radiation that reaches the earth is absorbed causing it to heat up. The earths radiates energy back towards to space as IR (heat). Troposphere absorbs this radiation and re-emits it further causing the earth to heat up.

Hint 34

a lit of absorption and emitted stuff!

Front 35

Is the greenhouse effect essential for life?

Back 35

Yes cause other whose the earth would be 30° cooler.

Front 36

What is it that we don't need (regarding the greenhouse effect)?

Back 36

An ENHANCED Greenhouse effect

Front 37

What are the main greenhouse gasses?

Back 37

Water vapour. carbon dioxide and methane

Hint 37

three of them

Front 38

What are greenhouse gasses?

Back 38

A gas which their molecules absorb IR radiation to make the bonds in the molecule vibrate more.
This extra vibrational energy is passed on to other molecules in the air by collisions, giving the other molecules more kinetic energy and so overall raising the overall temperature.

Front 39

What does the effect a molecules have of the green house effect depend on?

Back 39

•How much radiation one molecule of the gas absorbs
•How much of that gas there is in the atmosphere

Front 40

What is causing the enhanced greenhouse effect?

Back 40

•burning fossil fules (increasing CO2)
•Chopping down trees (reducing photosynthesis -> increasing CO2)
•more cows (leading to an increase in methane)

Front 41

What do Maxwell-Boltzmann distributions show?

Back 41

How many molecules have the activation energy ( or higher) so are as to react.

Hint 41

something to do with energy