Exam Questions Flashcards
Give a reason why the carbon compounds produced are different
Incomplete combustion
Why is sulfur dioxide produced in a petrol engine?
Sulfur impurities react with oxygen in the air
Many scientists are concerned about the carbon dioxide released from burning fossil fuels such as petrol
Because CO2 causes global warming and sea level rises causes flooding
Why does the government and people often ignore scientists’ predictions of an earthquake?
Not to cause panic and worry
Not much they can do
Not always right, exact time or how severe
What is Wegener mean by continental drift?
All continents started together over time they have slowly mover apart and still are
The atomic umber of an atom is the number of….
Protons
The mass number an atom is the number of ….
Protons and neutrons the nucleus
Titanium is more expensive than iron, why?
More stages
More energy required to extract
The air is removed from Reactor 2. An atmosphere of argon is used for the reaction between titanium chloride and magnesium metal, why?
Argon is un reactive
If it was air then oxygen would react with the magnesium
Steps for fractional distillation
The crude oil is heated to 350oC
Most of the compounds I. The Crüe oil evaporate
Any liquids flow down to the boot, of the column and the hot vapour ride up the column
When the hot vapour rise up the colum, the vapours cool
When a fraction in the vapour cools to its boiling point, the fraction condenses
The condensed fraction is separated and flows out through a pipe
Name two substances produced when poly(ethene) burns in the air
Carbon dioxide
Water
What is always given of in complete combustion?
Carbon dioxide
Water
Why has the percentage of CO2 decrease in the Earth’s early atmospher?
Plants photosynthesis
Dissolved in oceans
Miller and Urey used methane, ammonia and hydrogen for the Earth’s early atmospher, why?
The gases contain the elements which are needed for making amino acids
Miller and Urey’s experiment provides only weak evidence of how amino acids formed on earth, why?
It was an assumption, not now for a fact
Don’t know there was defiantly lightning
Calcium reacts with … To produce calcium carbonate
Water
Calcium hydroxide reacts with … to produce calcium carbonate
CO2
Buildings made of limestone are affected b the products from burning fossil fuels containing sulfur, why?
Sulfur reacts with oxygen to form sulfur dioxide
Acid rain produces from sulfur dioxide
Erodes buildings
Why may a gold ring not be made of 100% gold?
To soft
To expensive
Carbon dioxide is one if the main gases in the mixture of gases coming out of th kiln, why?
CO2 from limestone when combustion
Methane when burned produces CO2
What is he orientate of nitrogen in the air?
78%
Why does the mixture in the simple salad dressing separate?
They are immiscible
Mustard in the french salad dressing gasps molecules with hydrophilic and hydrophobic properties.
Explain why the french salad (contain olive oil and visiter) does not separate
Mustard is an emulsifier
Head - hydrophilic
Tail - hydrophobic
What is the test for unsaturated fats?
Bromide water
Orange to colourless if unsaturated
How do you harden vegetable oil?
Nickel catalyst used
Hydrogen reacts with the olive oil
Reaction at 60oC
In an equation of cracking hydrocarbons what do you always have to give?
C4H10
What is seen when sugar solution and yeast are fermented?
Fizzing
Why does aluminium react with iron oxide?
Because it is more reactive than iron so displacement takes place
Copper is extracted from ores containing a low percentage of copper compounds, why?
Very little of high grade ores
High demand
Why is it difficult to dispose of waste rock?
Waste rock takes a lot of space
Why is the extraction of pure copper expensive?
Large amounts of one ore to be mined
Many extraction stages
What is used in phytomining to remove copper compounds from the land?
Plants are used to absorbed the copper compounds and are later burnt
What type of reaction releases energy from a fuel
Exothermic
Ways of make alcohol from plants and their pros and cons
Fermented
Plants (with sugar like sugar canes) + yeast —————> alcohol
Pros: renewable
Cons: long, takes up land
High temperature Steam + ethene ----------------------------> alcohol Pros: less energy Cons: ethene = crude oil which is unrenewable, high temp needed so more energy
Why are new ways if extracting copper being researched?
Low high grade ore
Reduce environmental impact
3 ways to produce copper metals from its compound
Smelting (bio leaching + photosynthesis)
Reduction
Electrolysis
Properties of transition metals
Strong
Malleable
Good conducted
Problem with poor metals e.g gold
Too soft
Properties of aluminium
Malleable
Not corrosive
Low density
Properties titanium
Many stages
Low high grade ores
Large amount of energy
Cannot be extracted by carbon
Why should we recycle iron or steel?
Reduce energy
Less expensive
Reduce waste
Methods of smelting:
Bioleaching
Photomining
Two fuels which are rentable
Ethanol
Biodiesel
When alkanes are burnt what do they give of?
Burns to produce carbon and water
What does complete combustion of ethanol produce?
Carbon dioxide and water
What is released when hydrogen and oxygen is released?
Only produces water
Give two reasons why fraction from crude oil are cracked
More uses as fuels
To make alkenes
What is ethanol
Type of alcohol same two ways to produce alcohol
Suggest three ways of reducing the problems of plastic rubbish
Adding cornstarch
Biodegradable polymers
Recycle
What type of fuels are produced from vegetable oils?
Biofuels
Outline a method you could use to separate some oil from seeds
Crush seeds
Press seeds
Collect liquid
Separate oil from water
Reaction of hydrate vegetable oils
Hydrogen
60oC
Nickel catalyst
Process of photomining
Some plants absorb copper compounds through their roots. They concentrate these compounds as a result of this. The plants can be burned to produce an ash that contains the copper compounds. This method of extraction is called phytomining.
What is the process of bioleaching?
Some bacteria absorb copper compounds. They then produce solutions called leachates, which contain copper compounds. This method of extraction is called bioleaching.
What is smelting?
Copper can be extracted from these ores by heating them in a furnace, a process called smelting
Blast furnace:
To make iron
Iron oxide + carbon —–> iron + carbon dioxide
Or
Iron oxide + carbon monoxide —> iron + carbon dioxide
What is hydrophilic?
Head
Loves water
What is hydrophobic
Tail
Hates water
