Agriculture And Industry Flashcards
Things that help food production ( plant growth)
Fertilizers add nutrients for plant growth (NO3^-, PO4^3-, K+)
Mature adds organic matter for plant growth and soil improvement
Like or chalk added to the soil will alter pH of soil
Pesticides (insecticides, fungicides and weed killers) increase crop yields. Need to be biodegradable so don’t accumulate in food
chains
GM crops can be developed to give crops with desirable properties
Recycling of materials- principles of green chemistry
Minimize waste
Reduce energy consumption
Reduce feedstock consumption
Kc - what does it mean
Equation for it
Kc= conc of products / conc of reactants
Number of moles = powers
Equilibrium constant at a specified temperature
Kc is a measure of…
Kc = small? Large?
How far a reaction proceeds
Small- mixture is largely reactants
Large - mixture Is largely products
What affect Kc?
Change in temperature.
Exothermic -
Temp affect on Kc
Temp increases = Kc decreases
Temp decreases = Kc increases
Endothermic reaction temp affect of Kc
Temp increases Kc increases
temp decreases Kc decreases
Name giant lattice examples (3)
Ionic, covalent network and metallic
Ionic lattices - what substances have this structure?
Examples
What type of particles does it contain?
How are the particles bonded?
Compounds of metals and non-metals
Eg- sodium chloride, calcium oxide
Type of particles - ions
How’re they bonded? Strong ionic bonds: attraction between oppositely charged ions
Covalent network what substances have this structure? Examples What type of particles does it contain? How are the particles bonded?
What substances have this structure- Some elements in group four and some of their compounds
Eg diamond, graphite, silica
Type of particles does it contain? Atoms
What bonds are present? Strong covalent bonds
Metallic what substances have this structure? Examples What type of particles does it contain? How are the particles bonded?
Substances - metals
Eg sodium, copper, iron
Type of particles - positive ions surrounded by delocalised electrons
What bonds present- strong metallic bonds, attraction of atoms’ nuclei for delocalised electrons
Name both types of covalent molecular (2)
Simple molecular and macromolecular
Simple molecular - what substances have this structure?
Examples
What type of particles does it contain?
How are the particles bonded?
Substances - some non metal elements and some non metal/ non metal compounds
Eg carbon dioxide, chlorine and water
Type of particles - small molecules
How’re the particles bonded weak intermolecular bonds between molecules, strong covalent bonds between the atoms within each molecule
Macromolecular- what substances have this structure? Examples What type of particles does it contain? How are the particles bonded?
Substances - polymers
Example - DNA, nylon, polyethene
Type of particles does it contain- long-chain molecules
How’re they bonded?
Weak intermolecular bonds, strong covalent infra bonds between atoms in the molecule
Ionic - typical properties
High mp and bp
Hard but brittle
Conduct electricity when molten to dissolved in water, electrolytes
Solubility in water - often soluble
Solubility in non polar solvents - generally insoluble
Covalent network typical properties
Very high mp and bp
Very hard if 3D
Do not normally conduct (except graphite)
Solubility in water - insoluble
Solubility in non polar solvents - insoluble
Metallic typical properties
Generally high melting point and bp (except Mercury)
Hard but malleable
Conduct electricity when solid or liquid
Insoluble in water (but some react)
Solubility in non polar solvents - insoluble
Simple molecular typical properties
Mp and bp low Soft Do not conduct electricity Usually in soluble unless molecules contain groups that can hydrogen bond Usually soluble in non polar solvents
Macromolecular typical properties
Bp and mp - moderate often decompose on heating
Vary in hardness, many are soft but often flexible
Do not normally conduct electricity
Solubility in h2o usually insoluble
Sometimes soluble in non polar solvents
Haber process equation and conditions
N2(g) +3H2 (g) (eq) 2NH3 (g) delta H = -92kJmol^-1
Iron catalyst , 450 degrees & 200atm
Affect of increasing temp and pressure on haber process
Increasing temp - shifts eq to left as forward reaction exothermic, increases rate eq is achieved
Increasing pressure increases both yield and rate, but is expensive and running costs are high.
Using catalyst speeds up the rate at which equilibrium is achieved.
Nitrogen gas consists of _____ molecules which are very _____ because of the ____ activation energy needed to start breaking bonds
Diatomic molecules
Unreactive
High
Denitrifying bacteria in soil
Nitrogen gas N2 oxi state 0
Dinitrogen (I) oxide (nitrous oxide) N2O oxi state +1
Nitrifying bacteria in soil
Nitrate (V) ion NO3- (aq) oxi state +5
Nitrate (III) ion NO2- (aq) oxi state +3
Root nodules in legumes, Bacteria and microorganisms in soil
Ammonium ion NH4+ (aq) oxi state -3
Car engines, thunderstorms, denitrifying bacteria in soil
Nitrogen (II) oxide (nitrogen monoxide) +2 NO(g)
Oxidation of NO in atmosphere
Nitrogen (IV) oxide nitrogen dioxide +4
NO2 (g)
N2O
NO
NO2 colour of gases
N2O and NO ARE COLOURLESS
NO2 is brown gas at rt
