inorganic

Question 1

Acid + alkali.
NaOH+HCl

Answer 1

NaOH (aq) + HCl (aq) → NaCl (aq) + H2O(l) NH3 (aq) + HCl (aq) → NH4Cl (aq)

Question 2

Dissolving sodium hydroxide in water

Answer 2

NaOH (s) → Na+(aq) + –OH(aq)

Question 3

Ammonia + water

Answer 3

NH3 (g) + H2O (l) → NH4 +(aq) + –OH(aq)

Question 4

Acid + metal oxide

Answer 4

CaO (s) + 2HCl (aq) → CaCl2 (aq) + H2O (l)

Question 5

Acid + carbonate

Answer 5

CaCO3 (s) + 2HCl (aq) → CaCl2 (aq) + H2O (l) + CO2 (g)

Question 6

Magnesium and water + Magnesium and Steam

Answer 6

Mg (s) + 2H2O (l) → Mg(OH)2 (s) + H2 (g) (very slow) NOTE: Mg(OH)2 is sparingly soluble
Ca, Sr and Ba all react readily with cold water to form the hydroxide and hydrogen
Mg(s) + H2O(g) → MgO (s) + H2(g) (reacts readily)
MgO is formed because the hydroxide is unstable at higher temps:
Mg(OH)2 → MgO + H2O

Question 7

Reaction with oxygen

Answer 7

Ca (s) + ½O2 (g) → CaO (s)

Question 8

Reaction of group II chlorides with NaOH - shows the solubilities of group 2 hydroxides

Answer 8

MgCl2 (aq) + 2NaOH (aq) → Mg(OH)2 (s) + 2NaCl (aq)
white ppt
e.g. BaCl2(aq) + 2NaOH(aq) → Ba(OH)2 (aq) + 2NaCl(aq
colourless sol

Question 9

Reaction of group II hydroxides with acid

Answer 9

Mg(OH)2 + 2HCl → MgCl2 + 2H2O
Ca(OH)2 + H2SO4 → CaSO4 + 2H2O

Question 10

Test for sulphate ion

Answer 10

STEP 1: Add d.HCl to remove ions which might interfere with the test:
2H+ + CO32- → CO2 + H2O

STEP 2: Add barium chloride:
Full eqn: BaCl2 (aq) + Na2SO4 (aq) → BaSO4 (s) + 2NaCl (aq)
Ionic Eqn: Ba2+ (aq) + SO42- (aq) → BaSO4 (s)
white ppt

Question 11

Extraction of Titanium using Mg

Answer 11

TiCl4 + 2Mg → Ti + 2MgCl2

Question 12

Equation to show halogen, X2, acting as an oxidising agent:

Answer 12

Cl2 + 2e- → 2Cl-

Question 13

Displacement Reactions

Answer 13

Cl2 (aq) + 2Br- (aq) → Br2 (aq) + 2Cl- (aq
Colourless sol to orange sol
Cl2 (aq) + 2I- (aq) → I2 (aq) + 2Cl- (
colourless sol to brown sol
2I- (aq) + Br2 (aq) → I2 (aq) + 2Br- (aq)
colourless sol to brown sol

Question 14

Reaction of halide Ions with c.H2SO4

Answer 14

To form the hydrogen sulphate (white solid) and HX (misty white fumes) – NOT REDOX
NaX (s) + H2SO4 (aq) → NaHSO4 (s) + HX

Question 15

Testing for halide Ions in solution

Answer 15

STEP 1: Add d.HNO3 to remove ions that might interfere with the test:
2HNO3 + Na2CO3 → 2NaNO3 + CO2 + H2O
otherwise: 2Ag+ (aq) + CO32- (aq) → Ag2CO3 (s) ∴ CO32- gives a ppt if not removed
STEP 2: Add AgNO3 (aq)

Question 16

PPt formed with halide ions in sol (Ag+)

Answer 16

Ag+ (aq) + F- (aq) → AgF (aq) no ppt so doesn’t work as a test

Ag+ (aq) + Cl- (aq) → AgCl (s) ppt dissolves in d.NH3

AgCl(s) + 2NH3 (aq) → [Ag(NH3)2]+(aq) + Cl-(aq)

Ag+ (aq) + Br- (aq) → AgBr (s) ppt does not dissolve in d.NH3 but dissolves in c.NH3

Ag+ (aq) + I- (aq) → AgI (s) ppt does not dissolve in d.NH3 or c.NH

Question 17

form chloric(I)acid and HCl – DISPROPORTIONATION REACTION

Answer 17

Cl2 + H2O ⇌ HCl + HClO

Question 18

decomposition of Cl2 in water in presence of sunlight

Answer 18

2Cl2 (g) + 2H2O (l) → 4H+ (aq) + 4Cl- (aq) + O2 (g)

Question 19

Reaction of chlorine with sodium hydroxide (bleach)

DISPROPORTIONATION

Answer 19

Cl2 (g) + 2NaOH (aq) → NaClO (aq) + NaCl (aq) + H2O (l)