Group 2 Flashcards
Colour of Li flame test??
Red!! (Li - Lipstick)
❤️💋💄❤️💋💄
Flame test for K colour??
Purple (LilaK)
💜💜💜
Flame test colour for Mg?
Colourless!! (Magic Mg)
✨✨✨
Flame test colour for Sr??
Red!! (Sr RRR red)
❤️❤️❤️
Flame test colour for Na??
Yellow!! 💛☀️💛☀️
Sodium sunshine yellow
Flame test colour for Cs??
Blue 🌊💙🌊💙
Sea is blue Caesium
Flame test colour for Ba??
Green 🍏💚🐑💚
Baaaaa green grass
Flame test colour for Ca?
Red ❤️💉❤️
Ca in bones surrounded by RED blood
How to do a flame test??
Nichrome wire (can us Pt. but £££) inert metals!! 💜💛💚💙
c.HCl (dipped and cleaned)
💜💛💚💙
Non-luminous flame
💜💛💚💙
Trend of ionisation energy down group 2??
Decreases!
Explain the trend of ionisation energy down group 2?
Bigger atoms,
More shielding,
Easier to remove putter electrons,
Further from the +ve nucleus
The trend in solubility of sulfates down group 2??
Decreases!!!
aq
|
V
(s) e.g. BaSO4 (very insoluble barium meal used in veterinary!)
Trend in solubility of hydroxides down group 2??
Solubility increased!! Down group (s) >> (aq)
Solubility of SO4 ________ and solubility of OH _______ down group 2??
SO4 decreases!!! (BaSO4)
OH increases (they are opposites)
Trend in thermal stability down group 2??
Thermal stability increases down group 2!!!
The test tube melted!!
Why does thermal stability increase down group 2???
Be/Mg are stronger cations than Ba/Sr….. (They are smaller bigger nuclear attraction) This makes them more polarising to the anion!
A stretched elastic band is easier to break than a relaxed band !!
Explanation for how colours are produced in a flame test??
Heat energy absorbed from the flame excites electrons to higher energy levels - as e-s fall to lower energy levels energy is emitted in the visible light spectrum - we see colours!!!
How easily nitrates decompose can be tested by measuring ??? (2)
1) how long it takes until oxygen is produced (to relight a glowing splint)
✨✨✨✨
OR…
2) how long until brown gas (NO2) is produced. This needs to be done in a fine cupboard - NO2 is toxic !!!
How easily carbonates decompose can be tested my measuring???
How long it takes for carbon dioxide to be produced.
Test with lime water - which is saturated sol. CaOH. Turns cloudy with CO2!!
Group 2, nitrates decompose to form……
Oxygen + nitrogen dioxide + oxide !!
2M(NO3)2 (s). »_space; 2MO (s). + 4NO2 (g) + O2 (g)
Group 2 carbonates decompose to form….??
The oxide and Carbon Dioxide!!
MCO3 (s). »_space;> MO (s) + CO2 (g)
Group 1 ONE 1!!!!!
Trend of thermal stability of carbonates???
They are thermally stable - you can’t heat them enough with Bunsen burner to decompose them!!!
(Except Li2CO3)
Li2O and CO2
All group 1 carbonates are thermal stable except which element???
Li!!!! Li2CO3
To form Li2O and CO2
Group 1 ONE 1!!!
Nitrates decompose to form??
Nitrite and oxygen!!!!
2MNO3 (s) »_space;> 2MNO2 (s) + O2(g)
✨✨✨expect Li!!!
LiNO3 > Li2O, NO2, O2
