chemistry lesson

Practical work # 4 on the topic " Solving experimental problems on the topic "Substances and their properties" " - SUBSTANCES AND their PROPERTIES - LESSON PLANS for CHEMISTRY 11 class-lesson plans-lesson plans-author's lessons-plan-lesson summary - chemistry

Objectives of the lesson: to improve practical skills and skills of performing chemical experiments, observing the rules of OT and TB; to teach to apply knowledge of the theory of the topic in solving experimental problems.

Equipment: set of reagents, S₆H₅OH, SN₃Coos, Cao; unique indicator, alcohol lamp, test tubes, holder for prophet; sets for determining substances I, II, III, according to options.

Lesson progress

I. Organizational moment

Setting goals and tasks. Instruction on performing practical work on tasks in compliance with the rules of OT and TB: all reactions are recorded in molecular and ionic form; the work is paired.

II. Performance of tasks

III. Summarizing the lesson results

IV. Homework assignment

§ 21 № 6, № 7; § 22 № 5 (tasks).

Answers to practical work tasks

Option 1

1. HCl-hydrochloric acid, oxygen-free, monobasic, soluble, volatile, strong α → 1, stable.

NCSS — acetic acid, oxygen-containing, monobasic, soluble, volatile, weak α → 0, stable.

Experience:

 — the reaction takes place without heating, with a high speed and heat release.

 — without heating, the speed is very low; when heated, the reaction speed increases.

Conclusion: HCl is an inorganic acid, strong.

CH₃COOH-organic acid, weak.

However, both acids interact with the metal Zn and hydrogen is displaced from the acids. But because acids are different in strength, the reaction rates are different.

Experience:

There is a complete interaction of the main oxide with the acid to form a transparent solution of calcium chloride.

There is an interaction of an organic acid with the main oxide to form a soluble salt, but here it would be necessary to heat it slightly, increase the reaction speed.

Conclusion: organic and inorganic acids interact with the main oxides.

2. Creating a table:

 — pH alkaline, pH > 7. Universal indicator of color change > to blue under the influence of^{OH -}.

S₆N₅IT is a phenol, pH acidic, pH < 7. Universal indicator of color change to yellow-pink under the influence of H⁺.

 — a solution is neutral, the bipolar ion

The universal indicator turned green.

The response must specify the number of test tubes for certain substances.

 - sodium hydroxide, oxygen-containing base, monoacid, soluble, non-volatile, strong α > 1, stable.

 — phenol, organic compound, oxygen-containing, monobasic as acid, soluble, volatile, weak α → 0, stable.

 — alpha-aminoacetic acid, amphoteric compound, monoacid — monobasic, soluble, non-volatile, weak, stable.

3. Experience: sediment white, gelatinous:

a) Zn(OH)₂-base insoluble; amphoteric inorganic compound.

Experience:

 — aminoacetic acid; an amphoteric organic compound

Gas is released and water is formed:

 — aminoacetic acid-base

The formation of a transparent salt solution is observed.

When cooling, crystals fall out.

Option II

1. S₆N₅IT is a phenol, an organic compound, has acidic properties as a monobasic, oxygen-containing, soluble, volatile, weak, stable acid.

H₂SO₄-sulfuric acid, inorganic acid, oxygen-containing, dibasic, soluble, non-volatile, strong α → 1, stable:

a) p-p I₂; phenol interacts, there is a substitution along the aromatic ring;

H₂SO_4(p-p)does not react with I₂.

b) R-R NaOH

Output: C₆N₅IT is an organic compound that exhibits acidic properties, since an undivided pair of electrons of an oxygen atom comes into contact with the 6E^-π cloud of the aromatic ring, resulting in an oxygen atom of the group-OH will mix the common electron pair with the hydrogen atom in its direction, making it mobile. Phenol is an acid that is weaker than carbonic acid.

H₂SO₄is an inorganic, strong acid.

2. Creating a table:

NSl gives a strong acidic reaction.

 — the indicator color change to pink is influenced by H⁺.

 the solution is alkaline, pH > 7. the Universal indicator has changed color > to blue under the influence of^{OH -}.

CH₃COOH is acetic acid, the solution is slightly acidic, pH < 7

The universal indicator changed color to yellow-pink under the influence of H⁺.

The response must specify the number of test tubes for certain substances.

 — hydrochloric acid, oxygen-free, monobasic, soluble, volatile, strong α → 1, stable.

 — potassium hydroxide, base oxygen-containing, monoacid, soluble, non-volatile, strong, stable.

 — acetic acid, organic acid, oxygen-containing, monobasic, soluble, volatile, weak α → 0, stable.

3. The response is the same as in option # 1.