OCEANS

What is the greenhouse effect

some infrared frequencies are absorbed by gasees in the troposphere and re - emit these in all directions including back down to the earth.

What do greenhouse gases absorb in atmosphere

infrared radiation.

What are examples of greenhouse gases

Co2
H20
CH4

What happens when the greenhouse gases absorb infrared radiation

this makes the bond in the molecule vibrate much more and this vibrational energy is transferred to neighbouring particles by colliding with them causing temp to rise

What is the enhanced greenhouse effect

more burning of fossil fuels
loss of trees - less co2 being removed as a result.
Farming - Gas released from cows like methane.

Bronsted lowry acids

These are proton donors

Bronsted lowry bases

proton acceptors.

What signs (+) and (-) are associated to bronsted lowry bases or protons

+ = bronsted lowry protons
- = bronsted lowry bases

Whats the difference is dissociation with strong acids , bases and weak acids , bases

Strong bases and acids will dissociate almost completely whilst weak acids , bases will dissociate poorly

Difference between production of h+ in strong and weak acids.

in a weak acid equilibrium lies to the left so h+ not produced.
In a strong acid Equilibrium lies to the right so H+ produced

difference between production of Oh- in strong and weak bases

in a strong base forward reaction favoured strongly so lots of oh - ions produced
in a weak base backwards reaction is favoured so not many oh - ions produced.

Conjugate acid and base pairing

any species that has gained a proton is the conjugate acid
any species that has lost a proton is the conjugate base.

HA + B - BH+ + A-

HA and A - = conjugate pair because HA gains a proton to form A -
BH+ and B = conjugate pair because BH+ loses proton to form B

What is a buffer

Chemical that resists change in PH when small amounts of acid or base are added.

dissociation of a salt in equilibrium

Salts dissociate strongly so equilibrium lies to the right

What happens when H+ is added to this buffer :
CH3cooh /\ Ch3coo- + H+
CH3COONA+ /\ Ch3coo - + NA+

H+ reacts with ch3coo- in solution and because there is a high concentration equilibrium shifts to the left.

What happens when we add a base ( oh -) to this buffer
CH3cooh /\ Ch3coo- + H+
CH3COONA+ /\ Ch3coo - + NA+

oh - reacts with na + . There is a low concentration of these but they can be reproduced from a high conenctration of Ch3COOH to counteract the change. EQB shifts right

What needs to happen for a substance to dissolve

the solvent bonds must break
substance bonds must break
new bonds formed between the solvent and substance

Polar solvents

molecules that have polarity

How do polar solvents eg ( h20) interact to ionic compounds

Delta + h attracted to negative ions and delta - O attracted to positive ions.

What is the difference between solvation and hydration

Hydration = water molecules surround the ions in a process called hydration
Solvation = if the solvent is not water its known as solvation

What needs to happen for ions to dissolve in a solvent

the new bonds formed must be the same strength or greater than those broken but if not substance is unlikely to dissolve.

Exception to the rule in regards to dissolving in polar substances eg h20.

Alcohols can dissolve in polar substances even though = non ionic substance as they can h bond with water molecules.

Non polar solvents dissolving traits.

Only have ID - iD forces.
alkanes dissolve better in non polar solvents as they can form id id forces between molecules

Lattice enthalpy

measures the size of ionic bond strength.

Standard lattice enthalpy

Enthalpy change when one mole of ionic compound is formed from its gaseous ions under standard conditions.

Enthalpy change of solution

Enthakpy change when one mole of an ionic substance is dissolved in the minimum amount of solvent to ensure no further enthalpy change is observed upon further dilution.

Enthalpy change of hydration

enthalpy change when 1 mole of aqueous ions is formed from gaseous ions.

Lattice enthalpy

size of the charge on the ion affects the strength of the ionic bond.

Size of the ion in relation to electrostatic attraction

Smaller the ion the stronger the electrostatic attraction between ions because they can pack more closely and more energy is required to overcome stronger forces.

How does charge affect enthalpy change of hydration

ions with a higher charge attract water molecules more strongly because electrostatic attraction is stronger.

How does size affect enthalpy change of hydration

smaller ions have a higher charge density so they can attract water molecules more strongly so there is a more exothermic enthalpy change of hydration .

What is entropy

This is a measure of disorder in a system .

How is Entropy measured from solids liquids and gases

Solids have the lowest level of disorder particles are arranged neatly in rows then liquids then gases.

How does the number of particles affect entropy change

if a reaction is in the same state but more moles are produced then entropy increases as more ways of energy distribution