高中化学教材常考实验总结及命题方式解读.docx

1、高中化学教材常考实验总结及命题方式解读高中化学教材常考实验总结及命题方式解读The high school chemistry teaching material often tests the experiment summary and the propositional method interpretationThe first middle school of yimeng county in shandong province has increasedPreface: the proportion of chemical experiment in the college ent

2、rance examination questions is more and more big, the characteristics of the current college entrance examination test proposition are two: one is outstanding examination experiment of basic knowledge and basic operation ability, 2 it is to highlight the test experiment inquiry ability and it has cl

3、ear requirements in the exam outline. The textbook experiment often becomes the carrier of examination students experiment inquiry ability proposition. The importance of experimental textbooks is self-evident, therefore, in view of the present experiment in the teaching material distribution is more

4、 dispersed, the present situation of the students are difficult to master, my teacher organized a group for the finishing, now sent to you.A solution of the concentration of a certain substanceTake the example of the NaOH solution of 100ml1.00mol/L.1, steps: (1) (2) weight: 4.0 g (keep a decimal pla

5、ces) : dissolve (3) (4) transfer solution after cooling to room temperature in the beaker, transfer (5) the capacity: the washing (6) the distilled water into the volumetric flask, when the liquid level from a scale line 1-2 cm, use glue dropper head drops with distilled water to their lowest level

6、concave liquid level and scale line at the same level (7) shake: cover the cork, upside down and shake bottle label (8) : indicate the name of the drug, concentration on the label.Instrument: (by means of the procedure)Tray balance, spoon, beaker, glass rod, 100mL volumetric bottle, glue head droppe

7、rConsiderations:(1) volumetric flask: only one measuring line, and marked with temperature and range specifications, can only be used to produce the volume of solution on the bottle. (the other USES of temperature and range specifications are burette, measuring tube)(2) common volumetric flask: 50 m

8、L, 100mL, 250mL, 500mL, 1000mL. If 480mL and 240mL of solution were made, the 500mL volumetric and 250mL volumetric flask should be used respectively. When writing the instrument, the container must indicate the specification, and the tray balance cannot be written as a tray libra!(3) the bottle mus

9、t be checked before it is used. Methods: to add a small amount of water into the volumetric flask, plug the cork, with your index finger to resist the cork, with his other hand fingers hold the bottom of the bottle, the bottle upside down to come over, if not leak, with stand, spin the bottle stoppe

10、r plug tight after 1800, upside down without leaking again, just can use. (the split funnel and the burette should also be checked before use.)(4) the propositional Angle: the quantity of solid and liquid required for the calculation, the missing and the choice of the instrument, and the analysis of

11、 the error of the experiment.Two, Fe (OH) 3 gel preparation:Step 1: add the saturated solution of FeCl3 to the boiling water, continue to boil until the solution is reddish brown and stop heating.Operate the main points: four steps: first boil, then add the saturated FeCl3 solution, then boil to red

12、dish brown, and stop heatingThe chemical equation involved: Fe3 + + 3H2O Fe (OH) 3 (colloid) + 3H +One emphasis is to use equals, and the second is to indicate the colloid, not the precipitate, and the third is heating.Thesis: the writing of the process and the corresponding ion equationThree flame

13、reaction:Step: wash - burn - dip - burn - burnThe experiment USES platinum or wireThe flame color reaction can be either a single substance or a compound, a physical property4, Na, the flame of K: yellow, purple (through blue cobalt glass)5, a substance ACTS as a flame color. There must be a yellow

14、flame. There may be KPropositional Angle: experimental operation procedure and the flame color of Na and KFour, Fe (OH) 2 preparation:Experiment phenomenon: white precipitate immediately convert gray green, turn to reddish brown precipitate.2, the chemical equation is Fe2 + + 2OH - = Fe (OH) 2 + O2

15、+ 2H2O = 4e (OH) 33, considerations: (1) made of ferrous salt solution used must be new, NaOH solution must boil, (2) under the burette should be inserted into the liquid, (2) are often liquid surface with a layer of oil film, such as benzene or food oil (to prevent the oxidation of the oxygen).Prop

16、ositions: the phenomena of preparation, the writing of equations and the reasons for taking measuresFive, the preparation of silicic acid: 1, steps in a test tube with 3 to 5 ml Na2SiO3 saturated solution, drip 1-2 drops of phenolphthalein solution, reoccupy chase glue dropper head drop join dilute

17、hydrochloric acid, and while oscillation, solution to become lighter in color and close to disappear when the stop.Phenomenon: transparent silicate gel is formedChemical equation: NaSiO3 + 2HCl = H2SiO3 + 2NaCl (weak acid in strong acids)The NaSiO3 solution is based on SiO32 - hydrolysis, which make

18、s the phenolphthalein test liquid red.Vi. The test of important ions:1, Cl: add the AgNO3 solution, and add the dilute nitric acid, if it produces white precipitate that does not dissolve in dilute HNO3. Or the nitric acid solution (excluding CO32 - interference), and the addition of an AgNO3 soluti

19、on, such as a white precipitate, indicates the presence of Cl2, so42-test: add the hydrochloric acid first, if there is a white precipitate, filter first, then add the BaCl2 solution in the filtrate, and the white deposit can be proved. If there is no precipitation, the solution is put into the solu

20、tion of BaCl2.Angle of propositional: testing method, other than miscellaneous, precipitation washing and relative purity calculationThe laboratory method of ammonia gasHow it works: 2nnh4cl + Ca (OH) 2CaCl2 + 2NH3Collect: air to the lower air (a piece of cotton to avoid the air convection)3, check

21、with: (1) put wet red litmus paper tube mouth, if the test paper turned blue, that has its full collection of ammonia (2) will dip in with the glass rod near the tube mouth of the concentrated hydrochloric acid, appear a large number of white smoke, the proof has its full collection of ammonia gasDr

22、y method: alkali lime is dry (not without water and calcium chloride)Device diagram: the unit of solid and solid heating gas is the same as the oxygen systemExpansion: ammonia or concentrated ammonia can be used to make ammonia either in lime or caustic sodaPropositional Angle: the status of ammonia

23、 as the only experiment in the gas of high school chemistry experiment is immeasurable. The main Angle is: the principle of reaction, collection, drying and examination, and the basis of this kind of research.Experiment with fountainsExperiment principle: ammonia is very easy to dissolve in water, e

24、xtruding glue head dropper,A small amount of water can dissolve a large amount of ammonia (1:700), causing the pressure to decrease rapidly in the flask.The outside atmosphere pushes the water in the beaker to the flask above,So NH3, HCl, HBr, HI, SO2, etcGases can dissolve in water to form a founta

25、in.Experimental phenomenon: the production of red fountains (ammonia dissolved in water form alkaline solution, phenolphthalein is shown red in alkali)The key to the experiment: the ammonia should be full of the flask should be dryExperiment: CO2, H2S, Cl2 and other water cant form fountains, but th

26、ey can form fountains with NaOH solutionExperiments on the reaction of copper and concentrated sulfuric acidExperiment principle: Cu + 2H2SO4Phenomenon: after heating, the magenta solution in the test tube fades.Or the purple litmus test in the test tube turned red; Pour the solution into a beaker o

27、f water. The solution is black and blue.3, the reason explanation: the substance that is black is formed by the oxidation of concentrated sulphuric acid, CuO and the dilute sulfuric acid reaction produces CuSO4 solution.Because this reaction is quick, make use of copper wire, convenient to pull out

28、in time, reduce pollution.The properties of SO2 and the exploration of the products, green chemistry and the treatment of exhaust gas.10, aluminum heat reaction:1, experimental steps: put a small amount of dry iron oxide and the right amount of aluminium powder in paper funnel after mixing, topped w

29、ith a small amount of potassium chlorate in the mixture of solid and intermediate inserted a magnesium ribbon with sandpaper, lit.2, the experimental phenomenon: intense reaction immediately, shine, produce a lot of smoke paper funnel was burned, have red state liquid beads, fall into the evaporatin

30、g dish in the sand, liquid into solid black bead after cooling.Chemical reaction equation: Fe2O3 + 2Al 2Fe + Al2O3Precautions:(1) it is difficult to ignite the oxidation film on the surface of the magnesium strip.(2) the paper funnel inside the glass funnel is thicker and moistened with water in cas

31、e the funnel is damaged(3) a small amount of fine sand is needed for a steaming dish: one is to prevent the evaporation of the evaporating dish, and the other is to prevent the molten liquid from splattering.(4) dont be too close to people to prevent injuries.Propositional Angle: experimental proced

32、ure and chemical equation.11, neutralizing the heat experiment (understanding) :1, the concept: the heat released by the acid and alkali when the reaction produces 1 mole of waterNote: (1) acids and bases are the formula for strong acids and strong bases: h+ OH = H2O delta H = -57.3 KJ/mol(2) the value is fixed, it is the same as the heat of combustion, because it has a definite meaning, so the word expression is not positive or negative.The measurement of neutralizing heat:(1) to reduce the error, you must ensure that the hea