Chemistry - things to memorise

Chapter 1 - Experimental chemistry Experimental design 1.Name the most suitable apparatus for each situation (a) To contain about 100 cm3 of nitric acid: beaker (b) To measure 15 cm3 of sodium hydroxide solution: measuring cylinder (c) To measure the volume of carbon dioxide gas: gas syringe (d) To quickly dispense out three sets of 25.0 cm3 hydrochloric acid: pipette (e) To accurately measure the volume of alkali needed in titration: burette (f) To contain about 5 cm3 of salt solution: test-tube (g) To measure the mass of a bar of zinc: electronic balance 2. Precision of a non-electronic instrument is half of its smallest reading. Instrument Smallest reading Precision measuring cylinder 1 cm3 0.5 cm3 burette 0.1 cm3 0.05 cm3 thermometer 1 °C 0.5°C electronic balance 0.01g 0.01g digital stopwatch 0.01s 0.01s Methods of purification and analysis 1.Name the most suitable separation technique for each situation (a) Obtaining an insoluble solid from a mixture of the solid and a solution: filtration (b) Obtaining a soluble solid from a mixture of the solid in a solution. This solid does not decompose in heat. : evaporation to dryness (c) Obtaining a soluble solid from a mixture of the solid in a solution. This solid decomposes in heat. : crystallisation (d) Obtaining the pure solvent ( or water ) from a solution: simple distillation (e) Separating different liquids with different boiling points: Fractional distillation (f) Separating different liquids with different solubilities: Paper chromatography 2.Describe the procedure of crystallisation. - Heat solution until saturated. - Leave solution to cool for crystals to form. - Filter to obtain crystals. - Wash crystals with a small amount of cold distilled water. - Dry the crystals. 3. (a) The best way to test for the purity of a solid substance is to: check if it has a fixed melting point

(b) The best way to test for the purity of a liquid substance is to: check if it has a fixed boiling point (c) Impure substances or mixtures have a range of melting point and boiling points. Chapter 2 - Kinetic Particle Theory 1.Describe the arrangement and movement of particles in each state. (a) solid: movement: It is vibrating about fixed positions arrangement: It is very closely packed in an orderly manner (b) liquid: movement: It slides over one another arrangement: It is quite closely packed in a disorderly manner (c) gas: movement: It is moving randomly in all directions at high speeds arrangement: It is very far apart in a disorderly manner Chapter 3 - Atomic stru