Topic 4 Inorganics Flashcards
Group 2 + water —> ?
Metal Hydroxide (base) + H2(g)
Trend of reactivity in group 2
Increase
Group 2 + O2—>?
Metal oxide (base)
What is the appearance of a group 2 oxide
White solid
Does group 2 hydroxide solubility increase or decrease down the group
Increase
Solubility trend of group 2 sulfates
Decrease down the group
What do group 2 Carbonates decompose to
Metal oxides and carbon dioxide
What do group 2 nitrates decompose to
Metal oxides, nitrogen dioxide and oxygen
How does carbonate/nitrate stability change as you go down group 2 and why
Increase - large electron cloud in anion is distorted - distorted anions can decompose more easily - size of cation increase down group, charge density decreases so less distortion of anion
Are group 1 or 2 carbonated more thermally stable
Group 1
Which is the only group group 1 carbonate to decompose under a Bunsen and what does it form
Lithium carbonate —-> lithium oxide and carbon dioxide
What do group 1 nitrates decompose to
Group 1 Nitrites and oxygen
What does LiNO3 decompose to
Li2O, NO2 and O2
What are the formulas of nitrate and nitrite ions
NO3- and NO2-
What are 2 method to test thermal stability of nitrates
Measure how long it takes to produce an amount of oxygen. Use a gas syringe or a glowing splint. Or measure how long it takes to produce NO2 (toxic brown gas)
What is the method to test thermal stability of carbonates
Time to turn limewater cloudy (or use a gas syringe)
How do you get different colours in flame tests
Electrons absorb energy from flame, move to higher energy subshells, when they drop back energy released as photons. Different colours depend on wavelength of energy released.
Flame colour: Li
Crimson
Flame colour sodium
Orange
Flame colour potassium
Lilac
Flame colour rubidium
Red
Flame colour caesium
Blue
Flame colour calcium
Brick red
Flame colour Strontium
Crimson
Flame colour Barium
Green
Colour and state of group 7 elements
Fl2 - pale yellow gas
Cl2 - pale green gas
Br2 - brown - orange liquid
I2 - grey solid
What reaction occurs with halogens in cold alkali. Include equation
Disproportionation
X2 + 2NaOH —-> NaXO + NaX + H2O
What reaction occurs with halogens and HOT alkali give equation
Disproportionation
3X2 + 6NaOH —> NaXO3 + 5NaX + 3H2O
How is bleach made
Disproportionation of sodium hydroxide and chlorine to make sodium chlorate (I)
Three uses of bleach
-Treating water
-Bleaching paper and fabrics
-Cleaning agents
How does adding water to chlorine sterilise the water
Chlorate ion is formed (ClO-) which kills bacteria
What kind of agent are halide ions
Reducing - they lose an electron
Does reducing power of Halide ions increase or decrease down the group
Increase
What is the only possible set of product of sulfuric acid and chloride ions
NaHSO4 + HCl
What are the 2 possible set of products of Br- and Na2SO4
NaHSO4 + HBr and SO2 + Br2 + 2H2O
What are the 4 possible sets of products of I- and H2SO4
- NaHSO4 + HI
- SO2 + I2 + 2H2O
- 3I2 + S + 4H2O
- 4I2 + H2S +4H2O
What is the standard state of hydrogen halides
Gas
What forms when ammonia reacts with hydrogen halides and what is the visible observation
White fumes of ammonium halide
Test and colours for halides
Nitric acid then silver nitrate, white Cl-, cream Br-, yellow I-
How to confirm silver nitrate test for halides with ammonia
AgCl precipitate dissolve in dilute and conc ammonia, AgBr ppt dissolve only in conc ammonia AgI ppt is insoluble in ammonia
Carbonate test and how to confirm
Acid then limewater
Sulfate test
Barium Chloride after dilute HCl
Test for ammonium ions
Add NaOH and heat - use damp red litmus paper to test - ammonia will dissolve and turn litmus paper blue
Test for hydroxides
Turn red litmus paper blue
