Going down group 2, do elements become more or less reactive?
More reactive
Trend in first ionisation energy in Group2
More easily oxidised going down Group 2
Lower 1st IE
What do Group 2 Metals react with?
Oxygen
Chloride
Water
Acids
Equation for Magnesium + Oxygen
2Mg(s) + O2(g) → 2MgO(s)
Equation for magnesium + Chlorine
Mg(s) + Cl2(g) → MgCl2
Why does beryllium not react with water?
Because it has a thick oxide layer at the surface.
Equation for Magnesium and steam
Mg(s) + H20 → MgO(s) + H2(g)
Equation for magnesium and water
Mg(s) + 2H20 → Mg(OH)2 (s) + H2 (g)
What happens when cold water is added to calcium oxide
Mixture swells, freezes and a lot of energy and water vapor is released.
Equation for Calcium oxide with water
CaO (s) + H2O (l) → Ca(OH)2 (aq)
Equation of Magnesium oxide + HCL
MgO (s) + HCl (aq) → MgCl2(aq) + H2O
Equation of Calcium oxide + Nitric acid
CaO (s) + 2HNO3 (aq) → Ca(NO3)2 (aq) +H2O
Equation of calcium hydroxide + HCl
Ca(OH)2 (s) + 2HCl (aq) → CaCl2 (aq) + 2H2O
Equation of calcium hydroxide + Nitric acid
Ca(OH)2 (s) + 2HNO3 → Ca(NO3)2 (aq) + 2H2O
What is used to test for sulfate ions
Barium chloride
Definition of thermal stability
How much energy it can absorb before it breaks down
Going down group 2, does solubility in water increase or decrease?
Decrease
What Group 2 compounds are insoluble in water
Group 2 Carbonates
Which group 2 compound is soluble in water
Group 2 nitrates
Thermal stability trend in group 2
Thermal stability increase going down group 2
Charge density trend in group 2
Decreases down group 2
Relationship between charge density, polarity power and thermal stability
Smaller charge density = Greater polarising power= increase in thermal stability
Adding silver nitrate to Chloride ions
White Precipitate formed
Adding silver nitrate to Bromide ions
Cream precipitate formed
Adding silver nitrate to Iodide ions
Yellow precipitate formed
Adding dilute aqueous ammonia to Chloride ions
soluble
Adding dilute aqueous ammonia to Bromide ions
insoluble
Adding dilute aqueous ammonia to Iodide ions
insoluble
Adding concentrated aqueous ammonia to Chloride ions
soluble
Adding concentrated aqueous ammonia to Bromide ions
soluble
Adding concentrated aqueous ammonia to Iodide ions
insoluble
Silver nitrate + Sodium chloride
AgNO3 (aq) + NaCl(aq) → AgCl(s)+ NaNO3(aq)
Acid formed when water reacts with Hydrogen fluoride
Hydrofluoric acid
HF+ H2O →← H3O+ F
Acid formed when water reacts with Hydrogen chloride
Hydrochloric acid
HCl + H2O → H3O + Cl
Acid formed when water reacts with Hydrogen bromide
Hydrobromic acid
HBr+ H2O → H3O + Br
Acid formed when water reacts with Hydrogen iodide
Hydriodic acid
HI+ H2O → H3O +I
Reaction of ammonia and hydrogen bromide
NH3 (g) + HBr(g) → NH4Br(s)
Concentrated sulfuric acid + NaCl
Observation: misty fumes
Products: HCl
Concentrated sulfuric acid + NaBr
Observation:
Misty fumes, Brown fumes, colourless gas with choking smell
Products:
HBr, Br2, SO2
Concentrated sulfuric acid + NaI
Observation:
misty fumes, purple fumes or black solid, colourless gas with choking smell, yellow solid, colourless gas with rotten egg smell
Products:
HI, I2, SO2, S, H2S
Which group 2 compounds are soluble?
Group 2 nitrates
Group 2 chlorides
How to test for sulfate ions
Add barium ions
forms a white participate
The use of thermal decomposition
Use of heat to break down a reactant into more than one product
Thermal decompostion of MgCO3
MgCO3→ MgO + CO2
Trend in thermal decomposition down group 2
Decrease down
Why do Group 2 Carbonates get more thermally stable down the group
Cations get bigger
Less polarising power
Distort the electron cloud less
What is produced when Group 2 nitrates are decomposed on heating
Group 2 oxides
nitrogen dioxide gas
oxygen
Trend in melting point and boiling point in Group 7
Increase down the group due to more electrons
Trends in electronegativity in group 7
Decreases down the group
Trends in reactivity in group 7
Reactivity decreases down the group as atoms get bigger.
Observation of NaCl reacting with sulfuric acid
misty fumes
hydrogen chloride produced
Observation of NaBr reacting with sulfuric acid
misty fumes
brown fumes
chocking smell
Product: HBr, Br2, SO2
Observation of NaI reacting with sulfuric acid
misty fumes
purple fumes
yellow solid
Rotten smell
Produces: HI, I2, SO2, S, H2S