Inorganic Chemistry and the Periodic Table Flashcards
True or false, most group 1 metal carbonates decompose upon heating?
False. Most don’t decompose upon heating.
If a compound is hydrated, like blue copper sulfate, what does the structure contain?
Water.
Most hydrates decompose upon gentle heating to form what?
An anhydrous salt and water.
What is commonly chosen as a convenient string acid?
HCl.
What is commonly chosen as a convenient string base?
NaOH.
Acids don’t simply mix with water they do what with it?
They dissolve in it meaning they react with it to produce aqueous H+ ions.
True or false, all acids react with water to form aqueous H+ ions?
True. This is why dilute acids all react in a similar way.
What is a spectator ion?
An ion that is present in the solution for the reaction but takes no part in the reaction.
Acids react with more reactive metals to produce what?
Hydrogen gas and an ionic metal compound called a salt.
All alkalis dissolve in water to produce what?
Aqueous hydroxide ions.
During a neutralisation reaction what happens?
An acid reacts with a metal oxide or metal hydroxide to form a salt and water.
Acids and carbonates react to form what?
Salt, water and carbon dioxide.
What is an ionic precipitation reaction?
A reaction which produces a solid precipitate on mixing two solutions containing ions.
What happens when ionic compounds dissolve in water?
The ions move away from the crystals and each ion becomes surrounded by water molecules.
Ionic equations for ionic precipitation reactions need to show what?
The precipitate forming.
What acids are soluble in water?
All common acids.
Which metal hydroxides and carbonates are soluble in water?
Soluble hydroxides and carbonates are alkalis.
What is the solubility of calcium hydroxide in water?
Slightly soluble.
Which metal hydroxides and carbonates aren’t soluble in water?
All metal oxides and any metal hydroxides/carbonates that aren’t alkalis.
True or false, all nitrates are insoluble in water.
False. All nitrates are soluble in water.
All chlorides are soluble in water except which two?
Silver chloride and lead chloride.
Which two sulfates are slightly soluble in water?
Calcium sulfate and silver sulfate.
Which two sulfates are insoluble in water?
Barium sulfate and lead sulfate.
Are all sodium, potassium and ammonium salts soluble or insoluble in water?
They are all soluble.
Group on metals are known as what?
The alkali metals.
What are the physical properties of group 1 metals in their pure form?
They are soft and easily cut with a knife.
When freshly cut they are shiny but quickly become dull in air as they react with moisture and oxygen.
How are group 1 metals stored as not to react with moisture or oxygen?
They are stored in oil to protect them.
How many electrons are in the outer s-orbital of a group 1 metal?
1.
Describe the change in atomic structure as you go down group 1.
The charge on the nucleus increases.
The number of filled inner shells increases.
The number of electrons in the inner shells is always one less than the number of protons in the nucleus so shielding increases down the group.
Down the group the outer electron gets further away from the nucleus so the attraction to the nucleus reduces.
What is the only oxidation state for a group 1 metal in its compounds?
+1.
The alkali metals are powerful what agents?
Reducing agents.
All alkali metals react with what to form MOH compounds?
Water.
Does the rate of violence of alkali metals’ reaction with water increase or decrease down the group?
It increases down the group.
What would you see when sodium reacts with water?
The sodium melts and forms a shiny bead which skates on the surface of the water.
What would you see when potassium reacts with water?
A very violent reaction where the hydrogen catches fire and burns with a violet flame.
What happens when group 1 metals react with chlorine?
They react vigorously to form colourless, ionic chlorides that are soluble in water.
Are group 1 hydroxides soluble in water?
Yes.
Group 1 hydroxides are strong what?
Bases.
Group 1 carbonates have what general formula?
M2CO3.
How are group 1 carbonates unusual in terms of solubility?
They are all soluble in water.
How do group 1 carbonates dissolve in water?
The carbonate ion removes a H+ ion from the water making a hydrogen carbonate ion and leaving hydroxide ions forming an alkaline solution.
True or false, all group 1 carbonates decompose upon heating.
False, most of them do not decompose upon heating. The exception is lithium which breaks down into lithium oxide and carbon dioxide.
What is the general formula for group 1 nitrates?
MNO3.
At room temperature what is the appearance of group 1 nitrates?
White crystalline solids.
What is the solubility of the group 1 nitrates in water?
They are very soluble.
Are group 1 nitrates easier to decompose upon heating than other nitrates?
No they are harder to decompose. They melt upon heating them upon stronger heating they start to decompose.
Sodium and potassium nitrates decompose upon heating to form what?
Oxygen and the nitrite.
How is lithium nitrate the exception to group 1 thermal decomposition pattern?
It decomposes to form lithium oxide, nitrogen dioxide and oxygen like most other metal nitrates.
Compounds of sodium and potassium are widely used as chemical reagents, give a reason for this.
1) Their ions are unreactive so they often act as spectator ions.
2) Most sodium and potassium compounds are soluble in water.
3) Alkali metal ions are colourless in aqueous solution meaning they don’t interfere with colour change and if there is one it’s due to the negative ions.
What test can be done to identify group 1 ions which are generally very similar?
A flame test.
What negative ion is generally used for flame tests?
Chloride ions.
How do we get the colours in a flame test?
The energy from the flame excites the outer electron(s) to a higher energy level and as they travel back down the energy levels towards ground state photons are emitted which can correspond to colours we see.
What is the flame colour of lithium?
Bright red.
What is the flame colour of sodium?
Bright yellow.
What is the flame colour of potassium?
Lilac.
What is the name of the group 2 metals?
Alkaline earth metals.
Why are group 2 metals refereed to as earth metals?
They occur as minerals in rocks (chalk, marble and limestone are all forms of calcium carbonate).
Are all group 2 compounds soluble or insoluble in water?
They are all insoluble in water.
How do group 2 metals compare physically to group 1 metals?
They are harder and denser than group 1s, they have higher melting temperatures and have a layer of oxide covering their surfaces in air.
How can beryllium be used in industry?
It makes useful alloys.
How is magnesium manufactured?
It is manufactured using the electrolysis of molten magnesium chloride from sea water or salt deposits.
What metal is magnesium often alloyed with and why?
It is often alloyed with aluminium due to its low density making strong light alloys.
Barium is so reactive with air that it is often stored how?
In oil like the alkali metals.
What happens to the group 2 atoms’ structure as we go down the group?
The charge on the nucleus increases.
The number of filled inner shells increases.
What is the trend in reactivity down group 2?
It increases down the group.
Why do the first and second ionisation energies of each atom increase down group 2?
Increasing number of electrons in inner shells increases the atomic and ionic radii down the group.
The shielding effect of the inner electrons on the outermost electrons increases down the group.
Why don’t group 2 metals form 3+ ions?
The amount of energy required to remove a third electron from a group 2 metal means that it is not favourable to form 3+ ions. This is because the effective nuclear charge is far greater in the third electron due to it being in a closer energy level.
What oxidation state do all group 2 metals exist in in all their compounds?
2+ oxidation state.
Group 2 metals are all what kind of agents?
Reducing agents (apart from beryllium).
Apart from beryllium, group 2 metals burn in oxygen to form what?
White ionic oxides.
How does magnesium burn in air?
It burns in air with an intense white flame.
Why is magnesium burning the way it does useful?
It is used in fireworks and flares.
How does calcium burn in air?
It burns brightly with a red flame (strontium at sin the same way).
How does barium burn in air and what is formed that is different to other group 2 metals?
It burns in excess air with a green flame to form barium peroxide.
Do the group 2 metals react with water?
Yes.
How does rate of reaction of group 2 metals change throughout the group?
As you go down the group the rate of reaction with water increases.
What’s the difference between magnesium reacting with cold water and steam?
It will react far more vigorously with steam and very slowly with cold water. With steam MgO is produced whereas with cold water Mg(OH)2 is produced.
Calcium reacts with cold water to form what?
Hydrogen calcium hydroxide.
What happens in terms of solubility when calcium reacts with water.
Initially the Ca(OH)2 dissolves but solubility is low so that as more forms the solution becomes saturated quickly and a white precipitate forms.
What happens when barium reacts with cold water?
It reacts faster than the other group 2 metals and its hydroxide is more soluble.
All of the group 2 metals including beryllium react with chlorine on heating to form what?
White chlorides, MCl2.
Apart from beryllium oxide, the group 2 metals form what kind of oxides?
Basic oxides.
Group 2 oxides react with acids to form what?
Salts.
Magnesium oxide has a high melting temperature so is used for what?
It is used as a heat-resistant ceramic to line furnaces.
How does calcium oxide react with cold water?
Very vigorously to form calcium hydroxide.
How is magnesium hydroxide used in everyday?
It is the active ingredient in milk of magnesia and is used as an antacid and a laxative.
How is calcium hydroxide used everyday?
It is used as a test for carbon dioxide with the gas forming a white insoluble precipitate.
What is the trend in thermal decomposition of the group 2 carbonates down the group?
They become more difficult to decompose on heating down the group (more thermally stable down the group).
Why do group 2 carbonates become more difficult to decompose down the group?
As we go down the group ionic radii decrease meaning there is a reduced polarising power due to the same charge on a larger area (lower charge density). With a reduced polarising power they draw the electron cloud of the carbonate towards them less making the more thermally stable.
What is the trend in thermal decomposition of the group 2 nitrates down the group.
They become more difficult to decompose upon heating down the group (more thermally stable).
What happens to the solubility of group 2 sulfates down the group?
As we go down the group they get less soluble in water.
What is the flame colour of magnesium?
There isn’t a colour in the visible spectrum.
What is the flame colour of calcium ions?
Brick red.
What is the flame colour of strontium ions?
Bright red.
What is the flame colour of barium ions?
Pale/apple green.
Why are the halogens so dangerous and why are they never found free in nature?
Its because they are so reactive.
How are halogens found in nature, reacted in compounds with what?
They are found reacted with metals.
Why are halogen compounds so useful in everyday?
They are used in plastics, pharmaceuticals, anaesthetics and dyestuffs.
Under lab conditions what is the physical appearance of chlorine?
It is a yellow-green gas.
Under lab conditions what is the physical appearance of bromine?
It is a dark red liquid.
Under lab conditions what is the physical appearance of iodine?
It is a dark grey-purple solid.
All halogens are what kind of molecules?
Diatomic, X2.
What happens to the intermolecular forces between halogen molecules down the group and why?
The London forces increase down the group as the number of electrons in the molecules increases.
Why do boiling and melting temperatures of the halogen molecules increase down the group?
The molecules become larger and more polarisable meaning stronger intermolecular forces.
Why do halogens have similar chemical properties?
They all have seven electrons in their outer energy level.
Which is the most electronegative of the halogens?
Fluorine.
Fluorine is in what oxidation state in all its compounds?
-1.
How is fluorine used in industry?
To make useful compounds called fluorocarbons consisting of only carbon and fluorine.
Chlorine is usually in what oxidation state in its compounds?
-1.
When is chlorine not in an oxidation state of -1?
In compound with oxygen or fluorine it can be oxidised to a positive oxidation state.
What are the uses of chlorine in industry?
Polymerisation (PVC), disinfectant of water (treatment), bleach paper and textiles.
Is bromine a more powerful or less powerful oxidising agent than chlorine?
It is a less powerful oxidising agent than chlorine.
What is bromine used for in industry?
Uses include making flame retardants, medicines and dyes.
True or false, iodine is the most powerful oxidising agent of all the halogens.
False, iodine is the least powerful oxidising agent of all the halogens.
How is iodine used in industry?
Used to make many products such as medicines, dyes and catalysts.
Why is iodine needed in our diet?
It is needed so that the thyroid gland can make the hormone thyroxine, which regulates growth and metabolism.
What solvent is typically used to dissolve halogens in?
Generally hydrocarbon solvents such as cyclohexane are used.
What colour are the halogens when dissolved in hydrocarbons?
They are very similarly coloured to the free halogen vapours, for example, iodine is a violet colour in cyclohexane.
What are the halogens more soluble in, water or organic compounds?
Organic compounds.
Chlorine and bromine in what state are useful reagents?
Aqueous state.
Does iodine dissolve in water?
No.
What solution solvent is iodine typically dissolved in?
Aqueous potassium iodide solution.
What does iodine dissolve to form in aqueous potassium iodide solution?
I3- ions, from I2 and I-.
Are the halogens oxidising or reducing agents?
Oxidising agents.
Which halogen is the most powerful oxidising agent?
Fluorine.
Which halogen is the least powerful oxidising agent?
Iodine.
What is the trend in electronegativity down the halogens?
They become less electronegative down the group.
Chlorine and bromine react with s-block metals to form what?
Ionic salts.
Iodine reacts with metals to form metal iodides but what happens when iodine reacts with small cations (such as Li+ or Al+)?
They form bonds that are essentially covalent due to iodine’s polarisability.
Hot iron will burn brightly in chlorine to form what?
Iron (iii) chloride.
What happens when iodine reacts with iron?
Iron (ii) iodide is produced not iron (iii) because iodide ions reduce iron (iii) into iron (ii).
Does chlorine react with many non-metals?
Yes.
Which non-metals does chlorine not react with?
Carbon, oxygen or nitrogen.
Iodine oxidises hydrogen like the other halogens on heating to form hydrogen iodide, what’s different about the HI reaction?
It’s reversible.
What colour are the halide ions?
They are colourless, it is only the halogen molecules that have colour.
What colour is silver fluoride?
Colourless in solution as it is soluble.
What colour is silver chloride?
White.
What colour is sliver iodide?
Yellow.
What colour is silver bromide?
Cream?
What happens when silver chloride is left in sunlight?
It turns purple-grey with silver forming.
What happens when dilute ammonia is added to silver chloride?
The precipitate dissolves quickly to form a colourless solution.
What happens when concentrated ammonia is added to silver bromide?
The precipitate dissolves to form a colourless solution.
What happens when ammonia is added to silver iodide?
The precipitate will not dissolve.
What happens, in group 7, when a more reactive halogen comes into contact with a less reactive halogen ion?
A displacement reaction occurs where the reactive halogen oxidises the less reactive ion and takes its place in the compound.
If you warm solid sodium/potassium chloride with concentrated sulfuric acids, what are the products?
HCl (g) and NaHSO4 (s).
What type of reaction is sodium chloride + sulfuric acid?
Acid-base reaction.
Why can’t pure hydrogen bromide be produced from sodium bromide + sulfuric acid?
Because the bromide ions in HBr will be oxidised by the sulfur into bromine. Some HBr is given off but with Br2 , SO2 (g) and NaHSO4 (s).
What is the bad egg smell produced when NaI reacts with H2SO4?
H2S.
What type of reaction is NaI + H2SO4?
Acid base followed by redox.
What type of reaction is NaBr + H2SO4?
Acid base followed by redox.
How can hydrogen iodide be made purely?
By warming with phosphoric acid as phosphoric acid is not an oxidising agent.
