Studied by 0 people
How does Mg react with oxygen?
Burns easily, bright white light
How does Mg react with water
Vigorous reaction with steam, no reaction with water
How does Mg react with dilute HCl
Reacts vigorously
How does Mg react with dilute H2SO4
Reacts vigorously
How does Ca react with oxygen
Difficult to ignite, red flame
How does Ca react with water
Reacts moderately, forms a hydroxide
How does Ca react with dilute HCl
Reacts vigorously
How does Ca react with dilute H2SO4
Reaction slowed by the formation of a sparingly soluble sulfate layer on the metal stopping hydrogen bubbles from rising
How does Sr react with oxygen
Difficult to ignite red flame
How does Sr react with water
Reacts rapidly forms a hydroxide
How does Sr react with dilute HCl
Reacts vigorously
How does Sr react with dilute H2SO4
Reaction is quickly stopped by the formation of an insoluble sulfate layer on the metal
How does Ba react with oxygen
Difficult to ignite green flame
How does Ba react with water
Reacts rapidly forms a hydroxide
How does Ba react with dilute HCl
Reacts vigorously
How does Ba react with dilute H2SO4
Reaction is quickly stopped by the formation of an insoluble sulfate layer on the metal
What is the general formula for group 2 metals reacting with oxygen
2M(s) + O2(g) → 2MO(s)
What’s different about Sr and Ba reacting with oxygen
They also form a peroxide so they have 2 possible equations:
2M(s) + O2(g) → 2MO(s)
M(s) + O2(g) → MO2(s)
What is the general equation for group 2 metals reacting with water
M(s) + 2H2O(l) → M(OH)2(s) + H2(g)
which group 2 metal does not react with water
Be
What is a peroxide
A peroxide is a compound that contains an oxygen-oxygen single bond (−O−O−) or the peroxide ion (O2^2−).
Give the equation and reaction for Mg with cold water
Mg(s) + 2H2O(l) → Mg(OH)2(AQ) + H2(g)
Mg reacts extremely slowly with cold water
Give the equation and reaction of Mg with steam
Mg(s) + H2O(g) → MgO(s) + H2(g)
Reacts vigorously
What’s the general equation of group 2 metals reacting with dilute HCl
M(s) + 2HCl (aq) → MCl2(aq) + H2(g)
What’s the general formula of group 2 metals reacting with dilute H2SO4
M(s) + H2SO4(aq) → MSO4(aq) + H2(g) (for Mg and Ca the MSO4 is aq)
M(s) + H2SO4(aq) → MSO4(s) + H2(g) ( for Sr and Ba MSO4 is solid)
Going down group 2 what happens to the sulfates solubility
Decreases
What is the general equation of group 2 metal oxides reacting with water
MO(s) +H2O(l) → M(OH)2 (s) (this is for MgO and CaO they make a solid hydroxide)
MO(s) + H2O → M(OH)2(aq) (this is for BaO and SrO they form a aq hydroxide)
What’s the reaction between MgO and water
MgO is only slightly soluble in water, therefore a weakly alkaline solution (pH 10) is formed
What is the reaction of CaO and water
A vigorous reaction which releases a lot of energy, causing some of the water to boil off as the solid lump ems to expand and open (pH 11)
What is another name for calcium hydroxide when in solution
Limewater
What does a group 2 metal oxide + dilute hydrochloride acid make
Metal chloride and water
What does a group 2 metal oxide and dilute sulphuric acid make
Metal sulfate and water
What does a metal 2 hydroxide and dilute hydrochloride acid make
Group 2 Chloride (MCl2) and water
What does a group 2 metal hydroxide and dilute sulfúrico acid make
Sulfate (MSO4) and water
Which group 2 carbonate is soluble in water
BeCO3
What do all group 2 carbonates form when reacted with dilute HCl
Soluble chloride salts, water and carbon dioxide
Why can no further reactions happen with Ca, Sr and Ba carbonates
They from an insoluble sulfate layer which stops any dither reaction after the initial bubbling of CO2 seen
What does a group 2 carbonates and dilute HCl form
Chloride (MCl2), water and CO2
What does a group 2 carbonate and dilute sulfuric acid form
Sulfate, water and carbon
But the sulfate for Ca and Mg is aq so MSO4(aq)
The sulfate with St and Ba is solid so MSO4(s)
What is the equation of chlorine and alkali
Cl2(aq) + 2NaOH(aq) → NaCl(aq) + NaClO(aq) +H2O(l)
What’s the reaction of chlorine with water
Cl2 (aq) +H2O(l) → HCl(aq) +HClO(aq)
Give the equation of chlorine reacting with water in sunlight
2Cl2(g) +2H2O(l) → 4HCl(aq) + O2(g)
How can halide ions be identified in an unknown solution
By dissolving nitric acid and then adding silver nitrate solution drop wise
Why is nitric acid added to test for halide ions
To prevent false positive results from carbonate ions precipitating out with silver ions
What’s the chemical equation of silver nitrate and halide ions reacting
Ag+ (aq) + X- (aq) → AqX(s)
What colour would AgCl produce when testing for halides
White
What colour would AgBr produce when testing for halides
Cream ppt
What colour would AgI produce when testing for halides
Yellow
Why is ammonia added when testing for halides
Because the white, cream and yellow ppt can look similar
Which silver halide dissolves with dilute ammonia
Chlorine and it dissolves
Which silver halide dissolves with conc ammonia
AgBr
What is the general equation for halide ions and conc sulfuric acid
H2SO4 (l) + X- (aq) → HX(g) + HSO4 - (aq)
What is produced when conc sulfuirc acid is added dropwise to sodium chloride crystals
Hydrogen chloride gas
Give the equation and reaction for conc sulfuric acid and sodium chloride crystals
H2SO4 (l) + NaCl(s) → HCl(g) +NaHSO4(s)
and HCl gas is seen as white fumes
What is the equation and reaction for sodium bromide and conc sulfuric acid
H2SO4(l) + NaBr → HBr (g) + NaHSO4 (s)
but then conc sulfuric acid oxidises HBr which decomposes into bromine and hydrogen gas and sulfuric acid itself is reduce to sulfur dioxide gas:
2HBr(g) + H2SO4(l) → Br2(g) + SO2(g) + 2H2O(l)
The bromine is seen as a reddish brown gas
What’s the equation and reaction of sodium iodide and conc sulfuric acid
H2SO4(l) + NaI → HI(g) + NaHSO4 (s)
Hydrogen iodide decomposes readily
The sulfuric acid oxidises HI and is itself reduced to sulfur dioxide gas
2HI(g) + H2SO4(l) → I2(g) + SO2(g) + 2H2O(l)
Iodine is seen as a violet/purple vapour
The conc sulfuric acid oxidises HI and itself reduced to sulfur
6HI(g) + H2SO4(l) → 3I2(g) + S(s) + 4H2O(l)
Sulfur is seen a s a yellow solid then the conc sulfuric acid oxidises HI and itself reduced to hydrogen sufide:
8HI(g) + H2SO4(l) → 4I2(g) + H2S(s) + 4H2O(l)
Hydrogen sulfide has a strong smell of bad eggs
What is observed when I- reduces sulfuric acid to I2 and SO2
Purple vapour of iodine (I2) and chocking smell of sulfur dioxide (SO2)
What is observed when I- reduces sulfuric acid to sulfur (S)
Yellow solid of sulfur
What is observed when I- reduces sulfuric acid to hydrogen sulfide (H2S)
Rotten egg smell of H2S (hydrogen sulfide)
Why does iodide (I-) show multiple observations when reacting with sulfuric acid
Iodide is the strongest reducing agent or the halides, so it reduces sulfuric acid to different products
What is the use of BaSO4
In medicine for X rays on intestines as it is insoluble so not absorbed into blood (which is good as it’s toxic)
What can barium chloride or barium nitrate be used for
Tests for sulfate ions
What is magnesium hydroxide used for
It’s partially Soninke in water and is used to neutralise excess acid in the stomach and treat constipation
Give the equation of magnesium hydroxide and HCl
Mg(OH)2 (s) + 2HCl(aq) → MgCl2(aq) + 2H2O(l’
What are the equations involving magnesium extracting Ti
TiO2(s) + 2C(s) + 2Cl2(g) → TiCl4(g) + 2CO(g)
TiCl4(g) + 2Mg(l) → Ti(s) + 2MgCl2(l)
The titanium is extracted from its chloride by reduction with magnesium
What’s the general formula of group 2 hydroxides dissolving in water
X(OH)2 (aq) → X 2+ (aq) + 2OH- (aq)
What is the trend going down the group with solubility of group 2 hydroxides
Increases so OH- ions increases, increasing the pH of the solution
What is the trend of group 2 sulfated down the group
Decreases
