Experiment 2. Oxidation and reducing power of nitrous acid and Nitrites

A) Put 3-5 drops of KMnO₄ solution into the test-tube, acidify it by 2-3 drops of H₂SO₄ and add 5-7 drops of solution or 1-2 granules of NaNO₂. What properties does Sodium Nitrite show in this reaction? Write the reaction.

B) Fill the test-tube with 3-5 drops of NaNO₂, acidify it by 2-3 drops of H₂SO₄ solution and then add 3-4 drops of KI solution. Why does the color of solution change? Draw the reaction and determine the properties of NaNO₂ in this case.

Experiment 3. Oxidizing properties of nitric acid

Fill the test-tube with 3-5 drops of concentrated HNO₃, add piece of Copper. Make sure of gassing presence. Dilute the mixture by 20-30 drops of distilled water. How does the color of the gas change? Write the equation of oxidation-reduction reaction of cooper and concentrated and diluted HNO₃ interaction.

Experiment 4. Low soluble Phosphate formation

A) Add 1-2 drops of Potassium or ammonia thiocyanate solution to 3-4 drops of FeCl₃. The solution is colored in red. Draw the reaction equation.

Add some drops of Sodium or ammonia hydroPhosphate up to red color disappearance of Iron thiocyanate (III) and FePO₄ precipitation formation. Draw the equation of the reaction.

B) Put 4-5 drops of Na₃PO₄, Na₂HPO₄, NaH₂PO₄ solutions into three test tubes and adds the same volume of CaCl₂. Note the order of precipitation formation and draw the equation of the reactions.

Experiment 5. Representative reaction to phosphoric acid ions.

Add 5-6 drops of H₃PO₄ solution or its salt to 5-6 drops of molybdenum solution. Heat the mixture on water bath. The yellow precipitation of mixture (NH₄)₃H₄[P(Mo₂O₇)₆] is formed. Draw the equation of the reaction.

CHAPTER # 14. CHEMISTRY OF MAIN BIOMETALS

1. Introduction in General, Organic and Biochemistry, 7^th Edition, by Morris Hein, Leo R. Best, Scott Pattison and Susan Arena, Brooks/Cole Publishing Co., 2001. (Chapter 10.3, pp. 299-302);

2. http://www.chemsoc.org/viselements/pages/Visual Elements The Alkali Metals.html

3. http://www.chemsoc.org/viselements/pages/Visual Elements The Alkali-Earth Metals.html

3. http://www.chemsoc.org/viselements/pages/Visual Elements Group 13.html

4. http://www.hrw.com/science/mc/index/htm

1. The Alkali Metals

The elements of Group 1, the Alkali metals, are:

In each element the valency electron configuration is ns¹, where n is the period number. The last element, Francium, is radioactive and will not be considered here.

Date: 2015-01-12; view: 813