Buscar
Estás en modo de exploración. debe iniciar sesión para usar MEMORY

   Inicia sesión para empezar

them paper 2


🇬🇧
In Inglés
Creado:


Public
Creado por:
ruby hatton


0 / 5  (0 calificaciones)



» To start learning, click login

1 / 25

[Front]


where is crude oil found and how is it formed
[Back]


found in rocks, formed over millions of years from plankton remains found in mud

Practique preguntas conocidas

Manténgase al día con sus preguntas pendientes

Completa 5 preguntas para habilitar la práctica

Exámenes

Examen: pon a prueba tus habilidades

Pon a prueba tus habilidades en el modo de examen

Aprenda nuevas preguntas

Modos dinámicos

InteligenteMezcla inteligente de todos los modos
PersonalizadoUtilice la configuración para ponderar los modos dinámicos

Modo manual [beta]

Seleccione sus propios tipos de preguntas y respuestas
Modos específicos

Aprende con fichas
Completa la oración
Escuchar y deletrearOrtografía: escribe lo que escuchas
elección múltipleModo de elección múltiple
Expresión oralResponde con voz
Expresión oral y comprensión auditivaPractica la pronunciación
EscrituraModo de solo escritura

them paper 2 - Marcador

1 usuario ha completado este curso

Ningún usuario ha jugado este curso todavía, sé el primero


them paper 2 - Detalles

Niveles:

Preguntas:

285 preguntas
🇬🇧🇬🇧
Where is crude oil found and how is it formed
Found in rocks, formed over millions of years from plankton remains found in mud
What is a hydrocarbon
Molecules made up of hydrogen and carbon atoms only
Why are alkanes known as saturated molecules
Their carbon atoms are fully bonded to hydrogen atoms
What happens to viscosity as the size of hydrocarbon molecules increase
Viscosity increases, long chain hydrocarbons are extremely viscous and flow slower
What happens to flammability as the size of hydrocarbon molecules increase
Flammability decreases, short chain hydrocarbons are very flammable
What happens to boiling point as the size of hydrocarbon molecules increase
The boiling point increases, short chain hydrocarbons have very low boiling points due to weaker intermolecular forces
Explain the combustion of hydrocarbons
Carbon and hydrogen atoms in the fuel react with oxygen and become oxidised, if oxygen is unlimited, it produces CO2 and water, called complete combustion
Describe the stages of fractional distillation of crude oil
- crude oil is heated to a very high temp so it boils and all hydrocarbons evaporate and turn into a gas - crude oil vapour is fed into the fractional distillation column which is hotter at the bottom (350) and cooler at the top (25) - hydrocarbon vapours rise up the column + condense when they reach their boiling point - liquid fractions are removed and remaining hydrocarbons continue to rise up the column until they reach their boiling point and condense
Where are long chain hydrocarbons removed and why
At the bottom as they have very high boiling points
Where are short chain hydrocarbons removed and why
At the top as gases as they have very low boiling points and do not condense
What is a feedstock
A chemical used to make other chemicals
Give examples of fuels that can be made
Petrol, diesel, kerosene, heavy fuel oil, liquified petroleum gas
Give examples of feedstock that can be made
Solvants, lubricants, detergents, polymers
Why can't alkenes be used as fuels
Incomplete combustion, they can't release energy
Alkenes have at least one what
Covalent carbon to carbon double bond
Why does methene not exist
Methane only contains one carbon atom whilst alkenes need to have a double bond between two carbon atoms
Why are alkenes unsaturated
They have two less hydrogen atoms than the alkane with the same number of carbon atoms
What's the alkenes functional group
The carbon to carbon double bond
What is a functional group
The part of the molecule that determines how it reacts
What is produced during the combustion of alkenes and what is the process called
Carbon monoxide, co2, water and unburnt carbon particles, incomplete combustion
Why can't alkenes be used as fuels
Incomplete combustion, they can't release energy
Why can't alkenes be used as fuels
Incomplete combustion, they can't release energy
What is a hydrogenation reaction
Alkene + hydrogen --> alkane
What are the conditions for a hydration reaction to take place
Water must be in the form of steam, temp of 300, phosphoric acid catalyst, 70 atm
What is a hydration reaction
Alkene + steam --> alcohol
How would you increase the yield of alcohol in a hydration reaction
The reaction is reversible so unreacted alkenes and steam are passed back through the phosphoric acid catalyst
What is a halogenation reaction
Alkene + halogen --> di(halogen)(alkane)
Dichloropropane -->
Propene + chlorine
Advantages and disadvantages of producing ethanol with the hydration of ethene
A- yield of ethanol is high D- requires a high temp (lots of energy), ethene comes from crude oil which is finite
Equation for fermentation
Symbol: C6H12O6(aq) --> 2C2H5OH(aq) + 2CO2(g)
Advantages and disadvantages of producing ethanol with fermentation
A- low temp (less energy), sugar comes from plants and is renewable D- product is an aqueous solution of ethanol and has to be purified by distillation which requires energy
Conditions for fermentation
Yeast as a catalyst, 30degrees celsius, must take place in anaerobic conditions, in a slightly acidic solution
Alcohols combustion:
Alcohol + oxygen --> carbon dioxide + water
Alcohols reaction with sodium:
Alcohol + sodium --> sodium alkoxide + hydrogen
Symbol and word equation for the reaction of methanol, ethanol, propanol and butanol with sodium
Symbols: CH3OH + Na --> CH3ONa +H2 C2H5OH + Na --> C2H5ONa + H2 C3H7OH + Na --> C3H7ONa + H2 C4H9OH + Na --> C4H9ONa + H2
What happens when sodium alkoxides dissolve in water
They form strongly alkaline solutions
Alcohols combustion:
Alcohol + oxygen --> carbon dioxide + water
Why are carboxylic acids known as weak acids
They don't fully ionise/ only partially ionise in aqueous solutions
Name three features of the structure of DNA
Consists of two polymer chains made from monomers called nucleotides, there's bases, a double helix structure
State the percentages of the earths present atmosphere
78% nitrogen 21% oxygen 1% argon 0.4% other gases like CO2
Why can't scientists be certain of the worlds early atmosphere
The earth is around 4600 million years old so scientists cannot be certain about the early atmosphere
What did the earths early atmosphere mainly consist of
Carbon dioxide with little to no traces of oxygen
How were oceans first formed
The earth started to cool down and water vapour condensed to form oceans
What happened to CO2 levels as oceans were formed
It had decreased as CO2 dissolved in the oceans forming a weak acid which reacted with minerals in the sea to form precipitate which over time formed sediments of carbonate rock on the sea bed
What was the CO2 in the ocean used to make
Corals, shells of organisms like mussels
How did O2 start to get introduced into the atmosphere
Around 2.7b years ago, photosynthetic algae first evolved and produced oxygen
When could animals finally start to evolve
When oxygen levels reached a point where they could respire
How were the CO2 levels in the early atmosphere decreased
Fossil fuel formation, dissolved in oceans, photosynthesis
Explain how coal is formed
-remains of ferns and trees -plant remains covered with sediment rock and compressed -hight temp and pressure created coal
Why do the plants used to make coal not decompose when dead
Due to a lack of oxygen or acidic conditions that would allow bacteria to decompose the plants
How is crude oil formed
-plankton that have died -settle in mud and compressed by sediment -heat and pressure turn them into crude oil