Chemistry year 10 mocks Flashcards
Describe the gas test for chlorine
Put the gas in the beaker,get a piece of blue litmus paper and dampen it,put in the beaker if chlorine is present it will turn from blue to white
In the chlorine gas test why might the paper briefly turn red
because the chlorine dissolves in the water and forms hydrochloric acid
Describe safety steps for the chlorine test
wear a mask or do it in a fume cupboard
Describe the test for oxygen
Get a glowing splint put it in the beaker with the gas if oxygen is present the flame will relight
Describe the test for hydrogen
Get a burning splint and place it near the gas if you hear a pop hydrogen is present
Why do you hear a pop in the hydrogen test
because the heat energy burns the hydrogen with oxygen in the air causing it to form water
Describe the test for carbon dioxide
Have the gas in a tube and connect it to a beaker full of calcium hydroxide,bubble the solution if carbon dioxide is present the solution will go cloudy
Why does the calcium hydroxide go cloudy in the carbon dioxide test
because calcium carbonate is a solid and these particles make it appear cloudy
T or F fuels release energy when they are combusted
true
What are 2 examples of fuel
coal and hydrocarbons
What is coal used for
to generate electricity in power stations
What are hydrocarbons used for
to power vehicles such as cars
where are hydrocarbons found
petrol or diesel
Where is methane found and what is it used for
found in natural gas and used to power homes
what is meant by the term oxidised
when something is chemically combined with oxygen
T or F for complete combustion to happen you need plenty of oxygen
true
T or F carbon dioxide doesn’t contribute to climate change
faalse
Describe carbon monoxide
Is a toxic gas with no smell or colour
How is sulfur dioxide created
when coal is burnt it produces sulfur which then becomes oxidised
Where are oxides of nitrogen produced
inside car engines
T or F nitrogen and sulfur oxides cause breathing problems in humans
true
T or F nitrogen and sulfur oxides dissolve in rainwater to form acid rain
true
What are particulates
unburned hydrocarbons
What do particulates do
they increase the risk of heart and lung disease
T or F particulates cause global dimming
true
What is global dimming
Where tiny particles reflect sunlight away from the earth
What is the name of the atmospheric process which keeps the earth warm by absorbing radiation from the sun
greenhouse effect
What is the first step of chromatography
draw a baseline and mark it with a sample of ink then place it in a beaker with a shallow amount of water
What is a procaution you should take to make sure the results are accurate in the chromatography test
place a lid on top to stop it from evaporating
What is the second step of the chromatography test
the dyes will go up the paper producing different colours
when the chromatography test is finished what is the piece of paper then called
a chromatogram
What is the mobile phase and give examples
the phase that the substances can move in it would be the solvent that we used
What is the stationary phase and give examples
the phase where the substances can’t move this would be our paper
What is the calculation for the rf value
Distance travelled by the substance/distance travelled by the solvent
T or F using a different solvent or different paper will change the rf value in a chromatogram
true
How do you identify the chemical
calculate the rf value then look it up in a database,if there are other chemicals with the same rf value repeat it with a different solvent
Name 4 examples of fossil fuels that come from sedimentary rocks
oil,petroleum,natural gas,coal
what were fossil fuels formed from
dead organic material such as plants or animals
Describe how fossil fuels were formed from dead organic material
as the fish or plants died they sank to the bottom of the ocean,over time they were covered in layers of mud,pressure from sediments and heat turned them into fossil fuels
Where do we find coal
in sedimentary rocks
Where do we find oil
between layers of sedimentary rocks(shale)
Where do we find natural gas
in pockets above the oil
T or F one carbon atom can form 4 strong bonds
true
What is a hydrocarbon
Any compound that is formed from hydrogen and carbon only
Describe methane
It is the smallest alkane and it’s structure is CH4
Describe ethane
the second smallest alkane and it’s structure is C2H6
Describe propane
the second biggest alkane and it’s structure is C3H8
Describe Butane
the biggest alkane and it’s structure is C4H10
What are the 4 main alkanes
Methane,ethane,propane,Butane
What are the 4 main alkanes reffered to as
Homologous series
What is a homologous series
similar properties which react in a similar way
What is the general formula for the 4 main alkanes
Cn H2n+2n
How does the general formula work
if an atom contains n carbon atoms it will have 2x plus two hydrogen atoms
Are alkanes saturated compounds
yes
What does a saturated compound mean
every carbon atom has 4 covalent bonds
T or F crude oil is a mixture of different hydrocarbons
true
How do you separate out crude oil
through fractional distillation
T or F the shortest hydrocarbons are the most flammable so they make the best fumes
true
What is fracking
a thermal decomposition reaction
What is the process of catalytic cracking
vaporise your long chain crude oil,then pass it over the powdered alliminium oxide,as the hydrocarbons come into contact with the catalysts they become split into 2 smaller hydrocarbons
What is the process of steam cracking
vaporise your hydrocarbons and mix them with steam,heat them at a high temp this will cause the hydrocarbons to split apart into 2 smaller chains
How does the word equation for cracking work
Long chain to smaller chain+Alkene
Alkene has to have the same amount of carbon atoms as the longer chain-smaller chains carbon atoms
Decane C10H22 can be cracked into ethene C2H4 and another hydrocarbon write a balanced equation for this
Carbon=10-2=8
Hydrogen=22-4=18
C8H18
T or F alkenes are also part of the Homologous series
true
What is the difference between alkanes and alkenes
Alkenes have double bonds while alkanes have single bonds so alkenes are unsaturated and alkanes are saturated
What are two key differences by alkenes
more reactive,if you add bromine water to alkenes it will decolorise the bromine water,
What is the test for alkenes
bromine water
what does simple distillation do
separates a liquid from a solid
What happens in fractional distillation
separating a mixture of different liquids from each other
What is the difference between simple and fractional distillation
fractionall has different boiling points
What is the test for fractional distillation
have a mixture of 2 liquids in your flask,they get heated into vapours then travel up the fractionating column,when they reach this they condense drip back in the flask and evaporate again the vapours attract the themometer which rises,it goes into the condenser and turns back into a liquid but it’s still a mixture of 2 liquids but because one of them is a lower boiling point it willbe the one that ends up in the beaker and soon after the one with the higher boiling point
What is the fractionating column
a tube with hundreds of glass beads
What would you do if the mixtures had very similar boiling points
you would have to carry out several rounds of fractional distillation
What is the name of the alkene with the formula C3H6
Ethene
What is produced when bromine reacts with ethene
1,2-dibromoethane
T or F methanol is an alcohol
true
T or F the functional group -OH is present in alcohol
true
What is the formula for butanol which has 4 carbon atoms in each molecule
C4H5OH
Which carboxylic acid is produced when butanol is oxidised
Butanonic acid
What is the word equation for fermentation to produce ethanol
glucose to ethanol+carbon dioxide
T or F anaeorobic respiration is an essential condition for the fermentation of glucose by yeast
true
What will be seen if propanic acid is added to a solution of sodium carbonate
Bubbles of carbon dioxide will be produced
What are the monomers in a protein polymer molecule
amino acids
what is potable water
water that is safe to drink
what are the rules for something to be classed as potable water
has to have a ph between 6.5 and 8.5,no micro-organisms,level of dissolved substances has to be fairly low
Give examples of surface water sources and what is meant by it
lakes,rivers,resevoirs,bodies of water that are exposed to the surface
what are aquifers
permeable rocks underneath the ground that traps water
Give examples of ground water and what it is
aquifiers,water found underneath the ground
what are the benefits of surface water
easy to access,replaced frequently
What is a disadvantage of surface water
when it’s hot it can dry up
What are the steps to obtain potable water
pass it through a wire mesh to filter out any big things,pass through a bed of sand and gravel which filters out any smaller things,sterilise it to kill any bacteria
What are 3 ways of sterilising
bubbling through chlorine gas,ozone,ultraviolet light
What is meant by desalination
extracting potable water from seawater
What is the disadvantage of desalination
it has to have a lot of energy so is very expensive
How do you desalinate water through distillation
It is the same as simple distillation but with a larger quantity of water
How do you desalinate water through reverse osmosis
pass salty water through a membrane and all of the microbes get trapped
what are the different types of waste water
domestic,aggricultural,industrial
What does domestic waste refer to
showers,toilets,sinks
How does domestic waste work
goes from the toilets to the sewage treatment plants
What does agricultural waste refer to
nutrient-run off,animal waste
What does industrial waste refer to
factories that make chemicals
How do we treat domestic water waste
remove any organic matters and harmful microbes
How do we treat agricultural water waste
remove any organic matters and harmful microbes
how do we treat industrial water waste
How does sewage treatment work
pass it through a mesh,let it sit in a settlement tank to undergo sedimentation,biological breakdown of organisms
What is the difference between effluent and sludge
sludge undergoes anaerobic and effluent undergoes aerobic
How do you make the effluent safe
pump oxygen into it
How do you make the sludge safe
it will produce methane which can be burned as an energy source
What does a reversible reaction mean
where the recatants can form the products when cooled and vica versa
What makes something an endothermic reaction and what would it mean if it was a reversible reaction
when it is being heated up to make the reactants a product and to get the product to the reactants it would be exothermic
What does equillibrium mean
Chemical equilibrium is a state in a reaction where the rate of the forward reaction is equal to the rate of the reverse reaction.
What term is used to describe a chemical reaction in which the forward and reverse reaction rates are the same?
dynamic equilibrium
T or F at an equilibrium the concentration of products remains constant over time
true
The equation for the Haber process is: N2 + 3H2 ⇌ 2NH3. What gases will be present at equilibrium?
The equation for the Haber process is: N2 + 3H2 ⇌ 2NH3. What gases will be present at equilibrium?
One of the stages in sulfuric acid production is described by this equation: 2SO2(g) + O2(g) ⇌ 2SO3(g). What will happen to the yield of SO3 if the pressure is increased
If the pressure is increased, the SO3 yield will go up as the equilibrium position moves in the direction which forms the fewest molecules of gas.
If the forward reaction in a reversible reaction is endothermic, what will be the effect of decreasing the temperature?
The effect of decreasing the temperature would be to decrease the amount of products at equilibrium as the equilibrium position moves in the backward direction which is exothermic.
What is the effect of decreasing the pressure on the following equilibrium 2NO(g) + O2(g) ⇌ 2NO2(g)?
Less NO2 will be produced
What effect on the equilibrium position is produced by adding a catalyst to a system in equilibrium?
It has no effect
What is the rate of a reaction
the speed of which reactants get turned into products
What is the equation for the rate of a reaction
quantity of products/reactants used/time taken
what do we use to measure mass change
top pan balance
what do we use to measure gas volume
inverted measuring cylinder or burette
what are 4 things that affect the rate of reaction
temp,concentration/pressure,surface area,catalyst
what is the collision theory
in order for particles to react they have to collide together with sufficient energy
what is sufficient energy also referred to as
activation energy
What does the rate of reaction depend on
the amount of energy that the particles have,frequency of the collisions
What will happen if we increase the tempreature to particles during a rate of reaction
they will gain energy so therefore will havemore successfull collisions which will increase the rate of reaction
what does concentration/pressure refer to
how many particles per unit of volume
what will happen if we increase concentration/pressure during a rate of reaction
there will be more particles per unit of volume so collisions will be more frequent
what will happen if we increase concentration/pressure during a rate of reaction
frequency of collisions will be higher so rate of reaction will increase
What are catalysts
substances that speed up the reaction without being used in the reaction themselves
What does a catalyst do
it lowers the activation energy
what are the most common sources of a catalyst
transistion metals like cobalt and nickel
what percentage of earths atmosphere is nitrogen
80
what % of earths atmosphere is oxygen
20
what % of earths atmosphere is other gases
under 1
What was the earth like in it’s first billion years
intense volcanic activity which produced lots of carbon dioxide,water vapour,nitrogen most of the atmosphere was carbon dioxide,as the water vapour condensed it turned into oceans and this allowed carbon dioxide to dissolve in it
how did carbon dioxide start to decrease
green plants and alga started to form and they were photosynthesisig
What would happen when algae and green plants died
they would fall to the bottom of the seabed over time sedimentary would form over them wich then condensed in sedimentary rocks over time oil,sediments and gas got trapped in this which stopped the carbon from getting back into the atmosphere
What are crude oil and natrual gas mainly formed from
dead plankton
where is coal formed from
from sedimentay rocks
What is limestone made of
calcium carbonate
What is the function of a ribosome?
protein synthesis
what does 1 micrometer equal
10 -6m
A type of white blood cell called a macrophage measures 5 x 10-5 m. What does it measure in micrometres?
50
If the actual size of a cell is 100 μm, and 10 cm in a book, what is the magnification of the image in the book?
1000
t or f the magnification of an image is x1000 the actual size
true
how have microscopes developed over the years
increased resolution,increased magnification
If a cell called a megakaryocyte measures 1 x 10-4 m, and a neutrophil measures 1 x 10-5 m, what is the difference in order of magnitude?
1 as 5-4=1
what is an advantage of the transition electron microscope
higher magnifications are possible
how do you set up a microscope on a high power
Focus on low power with the coarse adjustment, move the high power objective in line with the specimen, refocus on high power with the fine adjustment
How are xylem vessels adapted to the transport of substances in the xylem
Xylem vessels are adapted to transport by having no end walls, and their side walls are thickened.
How is a muscle adapted to its function
Muscle is adapted to bringing about movement as it contains protein filaments that slide over each other and cause contraction.
T or F mitochondria is present in eukaryotic cells but not in prokarytotic
true
