1What are the common oxidation states of oxygen and hydrogen?
Oxygen: –2, Hydrogen: +1
2What are the oxidation numbers of the metals in NaOH, MgO, and Al2O3?
Na → +1, Mg → +2, Al → +3
3What is the oxidation state of oxygen in hydrogen peroxide?
-1
4What oxidation state is hydrogen in metal hydrides like NaH?
-1
5What is the oxidation state of Fe in iron(III) chloride?
+3
6Write the chemical formula of a compound with sulfur at +6 and oxygen at -2.
SO3
7What is reduction?
Gain of electrons and decrease in oxidation number
8What is oxidation?
Loss of electrons and increase in oxidation number
9What is a reducing agent?
Species that donates electrons
10What is an oxidising agent?
Species that gains electrons
11What is a redox reaction?
A reaction involving both oxidation and reduction
12How do you balance Zn and Fe half equations?
Make electron numbers equal, then add: Zn → Zn²⁺ + 2e⁻, 2Fe³⁺ + 2e⁻ → 2Fe²⁺
13How do you combine Zn and Fe half equations?
Zn + 2Fe³⁺ → Zn²⁺ + 2Fe²⁺
14Why does ionisation energy decrease down Groups 1 and 2?
More shielding, less nuclear attraction, easier to remove electrons
15What is the reactivity trend in Group 1?
Increases down the group
16What is the reactivity trend in Group 2?
Increases down the group
17What are the products of lithium and water?
Lithium hydroxide and hydrogen
18What is the equation for sodium and water?
2Na + 2H2O → 2NaOH + H2
19What is formed when potassium reacts with oxygen?
Potassium oxide
20What is the equation for lithium and oxygen?
4Li + O2 → 2Li2O
21What do Group 1 elements form with chlorine?
Metal chlorides (e.g. NaCl)
22How do Group 2 elements react with oxygen?
2X + O2 → 2XO
23How do Group 2 elements react with water?
X + 2H2O → X(OH)2 + H2
24How do Group 2 elements react with chlorine?
X + Cl2 → XCl2
25What is formed when hydroxides/oxides react with dilute acid?
Salt and water
26What is the reaction between NaOH and HCl?
NaOH + HCl → NaCl + H2O
27What is the reaction between Mg(OH)2 and H2SO4?
Mg(OH)2 + H2SO4 → MgSO4 + 2H2O
28What is the reaction between Li2O and H2SO4?
Li2O + H2SO4 → Li2SO4 + H2O
29What is the reaction between BaO and HCl?
BaO + 2HCl → BaCl2 + H2O
30What is produced when Group 1/2 oxides react with water?
Metal hydroxides
31What is the reaction between CaO and water?
CaO + H2O → Ca(OH)2
32What is the solubility trend of Group 2 hydroxides?
Increases down the group
33What is the solubility trend of Group 2 sulfates?
Decreases down the group
34What is the thermal stability trend of Group 1 and 2 carbonates?
Increases down the group
35What is the thermal stability trend of Group 1 and 2 nitrates?
Increases down the group
36Why does thermal stability increase down Groups 1 and 2?
Lower charge density = less distortion of CO3²⁻ or NO3⁻
37What is the flame test colour for Na⁺?
Orange
38What is the flame test colour for Li⁺?
Red
39What is the flame test colour for K⁺?
Lilac
40What is the flame test colour for Rb⁺?
Red-violet
41What is the flame test colour for Cs⁺?
Blue-violet
42What is the flame test colour for Ca²⁺?
Brick red
43What is the flame test colour for Ba²⁺?
Green
44What is the flame test colour for Sr²⁺?
Red
45Why do some cations produce coloured flames?
Electron excitation and photon release
46How to identify carbonate and hydrogencarbonate ions?
Add acid → CO2 → limewater turns cloudy
47How to identify sulfate ions?
Add BaCl2 → white precipitate (BaSO4)
48How to identify ammonium ions?
Add NaOH + warm → ammonia turns red litmus blue
49What colour is aqueous chlorine?
Colourless
50What colour is aqueous bromine?
Orange
51What colour is aqueous iodine?
Brown
52Why are halogens at different states at room temp?
Different meltingoiling points; trend increases down the group
53Why does meltingoiling point increase down Group 7?
More intermolecular forces to overcome
54What is the electronegativity trend in Group 7?
Decreases down the group
55Why does Group 7 reactivity decrease down the group?
More shielding, harder to gain electrons
56When does a halogen displacement reaction occur?
More reactive halogen displaces less reactive one
57What type of reaction is halogen displacement?
Redox
58Why must halogen B be above A in Group 7 to displace it?
Reactivity increases up the group
59Which halogens can chlorine displace?
Bromine and iodine
60Which halogens can't bromine displace?
Chlorine and fluorine
61Why can't iodine displace chloride or bromide?
It is less reactive
62Word equation for chlorine and potassium bromide?
Chlorine + potassium bromide → potassium chloride + bromine
63Symbol equation for bromine and potassium iodide?
Br2 + 2KI → I2 + 2KBr
64Observation when chlorine is added to KBr?
Colourless → orange
65Equation for chlorine and sodium?
2Na + Cl2 → 2NaCl
66What is a disproportionation reaction?
One species is oxidised and reduced in the same reaction
67Equation for disproportionation of chlorine with NaOH?
2NaOH + Cl2 → NaCl + NaClO + H2O
68Equation for disproportionation of chlorine with water?
Cl2 + H2O ⇌ 2H⁺ + Cl⁻ + ClO⁻
69How do NaCl and NaF react with H2SO4?
Not oxidised, form HCl and HF
70How do bromide ions react with H2SO4?
2Br⁻ + H2SO4 + 2H⁺ → Br2 + SO2 + 2H2O
71How do iodide ions react with H2SO4?
8I⁻ + H2SO4 + 8H⁺ → 4I2 + H2S + 4H2O
72How to identify halide ions?
Add HNO3 + AgNO3 → observe precipitate; test solubility with NH3
73How do hydrogen halides react with water and ammonia?
They donate protons forming acids