C6.1 Flashcards
what things 2 things do plants need for photosynthesis
plants need carbon dioxide and water
what do plants need for healthy growth
plants need small amounts of essential elements (in the form of mineral salts)
how are mineral salts dissolved
mineral salts are dissolved in water as ions in the soil
where is nitrogen found
nitrogen is found in ammonium and nitrate ions
where is phosphorous found
phosphorous is found is phosphate ions
where is potassium found
potassium is found as K+ ions
why do farmers add fertilisers to soil
farmers add fertilisers to soil to make sure their crops get enough mineral salts
what do NPK fertilisers contain
NPK fertiliers contain all 3 minerals required for healthy growth
why are fertlisers used
fertilisers are used because they help crops to grow well and so increase the farmers crop yield
what is ammonia
ammonia is an important compound in the manufacture of fertilizer and other chemicals such as cleaning fluids and floor waxes
how is ammonia made
ammonia is made by reacting nitrogen with hydrogen in the habour process. it is a reversible reaction
what is the equation for ammonia
nitrogen + hydrogen → ammonia
what are some typical symtoms of deficiency of nitrogen
poor growth, yellow leaves
what are some typical symtoms of deficiency of phosporus
poor root gowth, discoloured leaves
what are some typical symtoms of deficiency of potassium
poor fruit growth, discoloured leaves
what are the raw materials of the Haber process
air, natural gas and steam
how is nitrogen manufactured
nitrogen is manufactured by the fractional distillation of liquified air
how is hydrogen manufactured
hydrogen is manufactured by reacting natural gas with steam
what are 4 different examples of fertilisers
ammonium nitrate, ammonium sulfate, ammonium phosphate, potassium nitrate
how is urea manufactured
urea is manufactured by reacting ammonia with carbon dioxide
which fertiliser has the highest nitrogen content
urea
what are the main stages of the haber process
nitrogen (extracted from the air) and hydrogen (obtained from natural gas) are pumped through pipes. the pressure of the mixture of gases is increased to 200 atmospheres. the pressurised gases are heated to 450 °C and passed through a tank containing an iron catalyst. the reaction mixture is cooled so that ammonia liquefies and can be removed. unreacted nitrogen and hydrogen are recycled
what are the main stages of making ammonium sulfate
Put some dilute sulfuric acid into a beaker. Add a few drops of methyl orange indicator. Add dilute ammonia solution drop by drop, stirring in between. Continue step 3 until the colour permanently changes from red to yellow. Add a few more drops of dilute ammonia solution. Pour the reaction mixture into an evaporating basin, and heat carefully over a boiling water bath. Stop heating before all the water has evaporated and leave aside for crystals to form. pour away excess water and leave the crystals to dry in a warm oven, or pat dry
with filter pap
what does a fertiliser factory do
a fertiliser factory will carry out several integrated processes to make fertilisers
what is the haber process
the haber process is used to produce ammonia
what does dynamic mean (reaction)
dynamic means when the forward reaction and the backward reaction are happening at the same rate
what does equilibrium mean (reaction)
the reaction has reached a point where the concentrations of reactants and products do not change overall
what is a reversible reaction
when the products can break down to re-form the reactants
when is equilibrium reached
equilibrium is reached when the forward rate and the backward reaction are happening at the same rate. once this happends the actual amounts of reactants and products do not change
do reversible reactions reach equilibrium
no - not all reactions can recah equilibrium
what is the equation involving hydrogen, nitrogen and ammonia
hydrogen + nitrogen ⇌ ammonia
what happens when the equilibrium is on the right
when the equilibrium is on the right there are more products than reactants
what happens when the equilibrium is on the left
when the equilibrium is on the left there are more reactnants than products
what happens when a chemical system, at equilibrium, is changed
when a chemical system at equilibrium, is changed the system will react to return the equilibrium and reduce the impact of the change you imposed
what happens the equilibrium if we added more products
the equilibrium shifts to the left
what happens the equilibrium if we remove products
the equilibrium shifts to the right
what happens the equilibrium if we add reactants
the equilibrium shifts to the right
what happens the equilibrium if we remove reactants
the equilibrium shifts to the left
what happens the equilibrium if we increase pressure
the equilibrium will shift towards the side with the least number of molecules
what happens to the equilibrium if the reaction is exothermic
the equilibrium shifts to the left
what happens to the equilibrium if the reaction is endothermic
the equilibrium shifts to the right
does the rate of reaction increase or decrease if we increase temperature
increasing temperature increase the rate of reaction. this decrease yield
what is the haber process
the haber process is an industrial chemical process that makes ammonia by reacting nitrogen and hydrogen together
what is the number equation for the haber process
N2(g) + 3H2(g) ⇌ 2NH3(g) (forward reaction is exothermic)
what material is used as a catalyst in the haber proces
iron
what is the effect of catalysts oin the haber process
catalysts do not change the equilibium concentrations of reacting substances in reversible reactions. they reduce the time taken to reach equilibrium
why is iron used a catalyst in the haber process
it is used because it is cheap and it helps to achieve an acceptable yield in an acceptable time
what is the contact process
the contact process is one of the stages involved in the manufacture of sulphuric acid
what is the equation for the contact process
2SO2(g) + O2(g) ⇌ 2SO3(g) (forward reaction is exothermic)
what happens to the equilibrium position if the temperature is increased, in the contact process
if the temperature is increased, the equilibrium position moves in the direction of the endothermic reaction. this means it moves to the left in the contact process
what happens to the equilibrium position if the pressure is increased, in the contact process
if the pressure is increased, the equilibrium position moves in the direction of the fewest molecules of gas. this means is moves to the right in the contact process
what is used as a catalyst in the contact process
vanadium oxide
why is vandium oxide used as a catalyst in the contact process
because it helps to achieve an acceptable yield in an acceptable time
what costs are involved in the production of ammonia
raw materials, equipment - purchasing and maintenance, energy, wages
why is 450°C used to control temperature in the haber and contact process
because it is low enough to achieve an acceptable yield however high enough to do this in an acceptable yield
is the rate of production low or high in batch production
the rate of production is low in batch production
is the rate of prodution low or high in continuous production
the rate of production is high is continuous production
is the cost of equipment low or high in batch production
the cost of equipment is low in batch production
is the cost of equipment low or high in continuous production
the cost of equipment is high in continuous production
do you need a large or small amount of workers for batch production
you need a large amount of workers for batch production
do you need a large or small amount of workers for continuous production
you need a small amount of workers for continuous production
are the shut down periods frequent or rare in batch production
the shut down periods are frequent in batch production
are the shut down periods frequent or rare in continuousproduction
the shut down periods are rare in continuous production
is the ease of automating the process high or low in batch production
the ease of automating the process is low in batch production
is the ease of automating the process high or low in continuous production
the ease of automating the process is high in continuous production
how does phytoextraction work
- plants are grown on an ore that contains lower amounts of metal. 2. the plants absorb metal ions through their roots and concentrate these ions in their cells. 3.the plants are harvested and burnt.
- the ash left behind contains a higher concentration of the metal than the original ore. 5.the ash is processed to obtain the metal
what is a disadvantage of phytoextraction
it is slow
what are some advantages of phytoextraction
it reduces the need to obtain new ore by mining. It conserves limited supplies of more valuable ores with higher metal content
what is bioleaching
when certain bacteria breaks down ores to produce leachate
what is leachate
an acidic solution containing copper (II)
what is an advantage of bioleaching
Bioleaching does not need high temperatures
what are some disadvantages of bioleaching
It produces toxic substances, including sulfuric acid, which damage the environment
which material is used as a cost-effective way to produce copper from the leachate
scrap iron
what is the equation that displaces copper from leachate
iron + copper(II) sulfate → iron(II) sulfate + copper
Where are metals found
Metals are found in the crust, combined with other elements in rocks known as ores
What is an ore
In industry, an ore is a rock that contains enough metal to make mining and extraction economical
Which metals do not need extraction
Metals that are found in the ground as uncombined elements do not require further extraction
How can compounds in ores be departed from the other elements
By using chemical reactions
What are 2 ways of extracting metals from their ores
Burning ores with carbon (reduction) and electrolysis. Electrolysis can be used to purify copper
Which metals can be extracted from their ores by reduction, using carbon, coke or charcoal
Zinc, iron and lead
Which metals can be extracted by electrolysis
Potassium, sodium, calcium, magnesium and aluminium
Which metals do not need to be extracted
Platinum, gold and silver
What is reduction
The removal of oxygen from a substance. Reduction is used to obtain the metal
What is the equation linking lead oxide and carbon
Lead oxide + carbon —> lead + carbon monoxide
What is an alloy
A mixture of at least one metal and another element. Alloys are strong because there are no layers to break apart
What is corrosion
The gradual destruction of a metal due to reactions with other chemicals in its environment
What is gold
An unreactive metal that does not corrode easily
What is rusting
The specific name given to the corrosion of iron. It is a chemical reaction between iron, oxygen and water
What ways are there to prevent rust
Galvanising (coat of zinc), stainless steel, painting/other protection to remove reactants for corrosion, sacrificial protection
