Chapter 3 Flashcards
(32 cards)
Polar covalent bond
The electrons that spend more time with hydrogen
Polar molecules
Have equal sharing of electron and is v-shape molecules
Cohesion
Cohesion is a phenomena that claims that multiple linkage of hydrogen bond allows it to structure like liquid. This contributes towards water and nutrients transport against gravity in plants
Adhesion
The clinging kid one substance to another. Adhesion Of water molecules to cell wall helps counter downward pull of gravity.
Surface tension
A measure of how difficult it is to stretch or break the surface of liquid.
Kinetic energy
Anything that moves has kinetic energy. It is commonly known as energy of motion
Thermal energy
Thermal energy is related to temperature. It is increases when temperatures is raised because kinetic energy increase, it is also transferred from a cold substance to a warm substance. Okie
Temperature
Is a measure of energy that represents the average kinetic energy of the molecules in a body matter, regardless of volu,e
Heat
Thermal energy in transfer from one body of matter to another is defined as heat
Properties of water
- high specific heat which allows it to stabilise temperature stems
- high surface tension which allows things to float
- ice floats
Specific heat capacity
Is defined as the amount of heat that must be absorbed or lost for 1g of that substance to change its temperature by 1C
Why water has a high specific heat
Heat is absorbed when hydrogen bond break and is released when hydrogen bond form. This helps keep temperature relatively steady within limit that permit life.
Evaporative cooling
Is based on waters high heat of vaporisation. The evaporative loss of the most energetic water molecules cools a surface .
Why does ice floats
It floats because ice is less dense than liquid due to air spaces in its structure. This properties allows life to exist under the frozen surface of lakes and polar seas.
Why is water a versatile solvent?
It is because it’s polar molecules are attracted to ions and polar substances that can form hydrogen bonds.
Hydrophilic
Substance that have affinity to water
Hydrophobic
Substance that do not have affinity to water
Molarity
The number of moles of solute per litre of solution is used to measure concentration in solution.
Mole
A mole is a certain number of molecules of a substance.
Molecular mass
It is measure in Dalton. It is same as mass of a mole of substance in grams
Ph
Ph=-log[H+]. PH declines as H+ concentration increases and PH increases as H+ concentration decreases.
Acidity and basity of water
A water molecule can transfer H+ to another water molecule to form H3O+
Buffer
Is a biological fluid that resist PH change. A buffer consists of an acid-base pair that combines reversibly with hydrogen ions, allowing it to resist PH change.
Ocean acidification
The burning of fossil fuel increases the amount of CO2 in the atmosphere. Some CO2 dissolves in water causing ocean acidification.
