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Hint
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Answer
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what is a nitrate ion
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NO3 -
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how much carbon does high-carbon steel contain
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0.6% - 1.2%
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how do you test for 3 metal hydroxides
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To test for copper 2, iron 2 and iron 3 ions, first add NaOH ( sodium hydroxide ) solution to sample and observe the colour.
If copper (ii) ions (Cu 2+) are present the precipitate is blue If iron (ii) ions ( Fe 2+ ) are present the precipitate is green If iron (iii) ions (Fe 3+ ) are present the precipitate is brownish red |
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why is an alloy stronger than a pure metal
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because an alloy has different elements with different sized ions which ruins the regular lattice arrangement of a pure metal. pure metals have a regular lattice arrangement so their layers can slide over each other, but alloys don't have this arrangement so their layers cannot slide over one another as easily.
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what is source of hydroxide ions
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alkali
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what happens when carbon is exposed to air
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only reacts with oxygen if strongly heated, it has a yellowish orange flame and produces carbon dioxide which is slightly acidic when dissolved in water
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when bases react with acids what form is the salt
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a colourless, aqueous solution
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describe the greenhouse effect
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the sun emits short wavelength radiation Earth absorbs and reflects this as long wavelength radiation greenhouse gases cannot absorb short wavelength but can absorb long wavelength greenhouse gases absorb reflected radiaiton they re-radiate it as heat energy towards space, Earth and other greenhouse gases then the greenhouse gases that have recieved radiation from other greenhouse gases do the exact same thing as the other greenhouse gases have done, reflect it towards other greenhouse gases, towards Earth and space so heat stays in the atmosphere for longer than it should this heats up the Earth This is good and vital for life, but if too extreme it can cause global warming |
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what do all acids contain
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hydrogen ions
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are sodium, potassium and ammonium containing compounds soluble
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yes
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what does brittle mean
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cannot bend without breaking, very unflexible, not malleable, etc
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what is high-carbon steel used in
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masonry nails, cutting tools
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what indicator turns purple in neutral
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litmus paper
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why is copper used in electrical wires
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good conductor of heat and electricity, ductile
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when an acid reacts with a base what is produced
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salt + water
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is chlorine dangerous
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yes, it's a toxic gas
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how do you extract a metal that's below carbon in the reactivity series
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react it with carbon via a displacement reaction, so the carbon displaces the metal from it's compound forming carbon dioxide and the pure metal
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when an acid reacts with an alkali what is produced
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salt + water
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how does coating work
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the coating acts as a barrier. Stops the protected metal from being exposed to the oxygen and water in the air. If coating breaks, metal will be exposed and corrosion can take place
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why is stainless steel resistant to corrosion
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it forms a strong, protective oxide layer
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what are alkalis called
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proton acceptors as they accept H+ ions
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what salt will sulfuric acid form
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sulfate
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how do you test for chlorine
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use damp, blue litmus paper, this bleaches white if chlorine is present
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if the salt is soluble, what question would you ask to find out what method you should use
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is the salt a potassium or sodium one
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how do you test for ammonium ions
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add sodium hydroxide to sample and warm it up. If ammonium ions are present then ammonia gas will form. To test for ammonia gas put damp, red litmus paper near sample, if ammonia gas is present the paper turns blue.
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What is steel an alloy of
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iron, carbon and other substances
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what colour flame does lithium burn with
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red
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what ions do acids contain
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hydrogen ions
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what is oxidation
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gain of oxygen or loss of electrons
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what state is iodine at room temperature
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dark grey solid
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what conditions does iron need to rust
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oxygen and water present
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what is stainless steel mainly comprised of
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carbon, nickel and chromium
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name the 5 group 7 elements in order of reactivity
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astatine, iodine, bromine, chlorine, fluorine
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why do we not use universal indicator in titrations
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because it has a wide range of colours depending on the specific pH, so the change is too gradual meaning it is hard to see when the exact end point of the titration is. It doesn't have 1 specific colour for an acid, neutral and alkali like other indicators.
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what happens when magnesium is exposed to air
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it reacts with the oxygen in the air to produce magnesium oxide which is in the form of ash, this burns with a bright, white flame. Magnesium oxide ( MgO) is a base and is slightly alkaline in water so can react with an acid to produce a salt and water.
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what happens when hydrogen is exposed to air
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it reacts with oxygen in the air explosively, producing water, with lots of hydrogen it can be dangerous, burns with an orangy yellow flame and burns very easily.
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how do you test for ammonia
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use damp, red litmus paper, this turns blue in the presence of ammonia gas, it also has a strong smell
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what is limewater
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calcium hydroxide
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what is a precipitate
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an insoluble, ionic, solid product of a chemical reaction
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are all group 7 elements diatomic
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no, astatine and tennessine are controversial, we are unsure if they exist, but some people say they do exist.
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describe sodium's reaction with water
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fizzing sodium floats and moves around on water's surface aggressively sodium melts into a silver ball sodium disappears |
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are nitrates soluble
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yes
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what is a metal displacement reaction
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a reaction where a more reactive metal pushes a less reactive metal out of it's metal compound
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what is a redox reaction
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a reaction containing reduction and oxidation
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what is an acid
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a substance that forms hydrogen ions when dissolved in water
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what is reactivity
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how easily an atom loses or gains electrons
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name the 3 most common greenhouse gases
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CH4 ----------------> methane CO2 ---------> carbon dioxide H20 ---------> water vapour |
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how does the sacrificial method work
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by attaching a more reactive metal than the protected metal, this ensures if the protected metal gets into contact with oxygen and water then corrosion will not take place since oxygen and water are reacting with the more reactive metal
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what state is astatine at room temperature
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black solid
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what is an oxidising agent
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a substance that oxidises another substance, so it itself is reduced
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if the salt is potassium sulfate, what method do you use
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titration method
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how do you test for oxygen
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use a glowing splint, this re-lights in the presence of oxygen
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an indicator remained colourless in acid what indicator is this
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phenolphthalein
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how do bases neutralise acids
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combining with the H+ ions in them
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how do you carry out a flame test
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an inert wire loop with a high melting point like nichrome or platinum is placed in concentrated HCl to remove impurites, to test it's purity, hold it to a flame, if it's colourless then it's pure and we can move on. Dip wire loop into your salt sample so some sticks to it. Then stick this in the roaring part of the bunsen burner flame, the blue bit, because this is the hottest part. Then the colour is observed, metal cations burn with a unique colour.
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do group 1 elements react with water
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yes
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what are acids called
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proton donors as they give away H+ ions
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what is a titration
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it's a method used to find out how much of an acid (or alkali) neutralises a known volume of an alkali (or acid). It's a neutralisation reaction
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what indicator turns yellow in alkali
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methyl orange
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why is aluminium used in power cables
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it is ductile and conducts electricity
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