AeL - Advanced eLearning :: Level 4 :: SANAKO Study Science Lab Portal

The Acids and Bases Strength

In this interactive moment, students are asked to use a battery, electrodes, a bulb, conductors and a Berzelius glass to make an electric circuit. Then, they have to take from the table 100ml of solution and pour it into the glass. Finally they have to close the electric circuit and compare the lighting bulbs.

Acid Strength

Students are asked to put 1g of Zinc into two Erlenmeyer glasses with rubber cork. Then, they have to pour some HCl (50ml) into the first one and into the second one CH3COOH (50ml). A curved glass tube passes through it and it is connected to a burette filled with water.

Reactions with Electrons Transfer: Evaluation Test

In this interactive test, students are asked to fill in the free spaces in the figure with two of the bands meaning two of the solutions. In case they form a galvanic cell, the equations of the processes in the electrodes will be shown.

Cells

In this interactive moment, students are asked to take a Berzelius glass with a solution of CuSO 4 1M and put a copper band into it. After that, they have to put a zinc band into another Berzelius glass with a solution of ZnSO 4 1M. The two bands are connected with some metal conductors to a voltmeter. The two glasses are connected by a salt bridge.

The Activity Series of Metals

: Students are asked to take 5 Berzelius glasses with a content of HCl 1M, aqueous solution of AgNO 3 1M, aqueous solution of CuSO 4 1M, aqueous solution of Pb(NO3)2 1M, aqueous solution of ZnSO 4 1M and steep a band of Cu, Pb, Zn. Then, they have to complete the table of results.

The Batching of Fe +2 Ions with Potassium Permanganate

Into an Erlenmeyer glass with an unknown quantity of Fe +2 the student has to add 30ml of distilled water, 10ml of sulphuric acid 20% and 5ml of phosphoric acid 85% (for complex Fe +3 ions that have been formed and which could colour the solution into a dark yellow one; in this case, at the end of the reaction, students cannot see its pink colour). After that, they have to use a solution of potassium permanganate 0,1M and titrate it until a weak pink turn.

The Identification of some soil pollutants

A soil sample contains potassium nitrate in excess. Students are asked to identify the fertilizer by using chemical reactions as follows: 20 g of soil and 50ml of distilled water are mixed and filtered. The ions are identified in the filtrate: K + and NO --- 3. Then, 2-3ml of filtrate is put into a tube and perchloric acid is added. A white precipitate like snow flakes indicates the presence of the K+ ion.

Soil Pollution-Determining the soil ph

In this lesson moment, a chemist has to analyse several types of soil. One was brought in an area where an ecological accident had happened: a tank with sulphuric acid had overturned. Students are asked to help him find the polluted soil by ph measurements.

The Identification of some Inorganic Pollutants of Water

In this moment, students are asked to perform an experiment to study the water pollution with different metals. Into an Erlenmeyer glass that contains water, there are added a few ml of NaOH mixture and Na2CO3 is stirred and filtered to avoid the interference caused by salts like Ca and Mg. In the filtrate obtained there are added some drops of (CH3COO)2Pb (lead acetate) and in the presence of hydrogen sulphide it is obtained a black precipitate of lead sulfide.

Establishing the Acidity of Water

In this interactive moment, students are asked to analyse 50 ml of water in a measuring cylinder. The water is introduced into an Erlenmeyer glass, adding 2-3 phenolphthalein drops and a solution of NaOH of 0,1M, until the coulour becomes persistent light pink. The result is expressed in the number of NaOH ml consumed in the titration of 1000ml of water.