Boric Acid & Hydrobromic Acid.pptx

Methods of Preparing Boric Acid

1. METHODS OF PREPARING BORIC ACID , PROPERTIES AND APPLICATIONS Instructor: Milgrace E. Nonesa , RPh

2. Boric acid Very weak acid with the formula;   BH 3 O 3 ,   H 3 BO 3 or B(OH) 3 . Other Names : Boracic acid , O rthoboric acid , Borofax used as a mild antiseptic in the medical field . As a chemical compound Boric acid acts as a tribasic acid. I t dissociates to such a small extent, it is a very weak acid that is actually used in water solution as an eye wash.

3. Boric acid Pure boric acid is a colorless, odorless, white powder or transparent crystals with a slightly oily feeling that slowly decomposes with heat at about 340°F (171°C). Boric acid loses water as it is heated, changing first into metaboric acid (HBO2 ) and then into pyroboric acid (H2B4O7) and eventually to boric oxide (B2O3). The three acids can be thought of as hydrates of boric oxide (B2O3). Orthoboric acid is fairly soluble in water (especially hot water), alcohol, and glycerine .

4. Boric acid

5. PROPERTIES OF BORIC ACID white solid that crystallizes from aqueous solutions as triclinic waxy plates. The crystal structure of boric acid consists of planar sheets of planar trigonal B(OH)3 molecules linked by hydrogen bonds .

6. APPLICATIONS OF BORIC ACID IN OUR DAILY LIFE M ost important uses of Boric acid is as a source of Boron Trioxide B 2 O 3 in glasses & other vitreous products, fiberglass, heat-resistant borosilicate glasses, ceramic glazes, porcelain, ceramics, crockery, enamels, artificial gemstones, and sealing and optical glasses. Boric acid has other applications like insecticide for cockroaches, black carpet beetles fungicide on citrus fruits .

7. In the medical field boric acid has extensive use in: mouthwashes nasal sprays eye-hygiene formulations. Boric acid can also be used as a fire-retardant in some occasions. Other important applications include preservatives for natural products such as wood and natural fibers.

8. AVAILABILITY OF BORIC ACID IN NATURE In nature, Boric acid exists in two forms, a G lassy form obtained by high temperature dehydration of boric acid, C rystalline form obtained by slow heating of metaboric acid. Boric acid occurs naturally in a number of locations where it has precipitated out of hot springs. It may occur then in the form of the mineral sassolite .

9. PRODUCTION OF BORIC ACID The most common method of producing boric acid is by : treating the relatively abundant borax with hydrochloric or sulfuric acid crystallizing out the boric acid that forms in the reaction.

10. PRODUCTION OF BORIC ACID A less common method of preparation involves the treatment of borax brine solutions with a chelating agent that binds to the borates present in the brine, which can then be converted to boric acid.

11. PRODUCTION OF BORIC ACID Boric acid can be prepared in the laboratory by : A cid hydrolysis of a variety of boron compounds, including halides, esters, salts, and hydrides. Boric acid is produced commercially by reactions of sulfuric acid with sodium borates , and with sodium and calcium borates or by reaction of sulfuric acid with: ulexite , a mixed sodium-calcium borate . Ulexite is a structurally complex mineral, with a basic structure containing chains of sodium, water and hydroxide octahedral. The chains are linked together by calcium, water, hydroxide and oxygen polyhedra and massive  boron  units. 

12. PRODUCTION OF BORIC ACID Boric acid is also produced from the borosilicate mineral datolite . Datolite   is a  calcium   boron   hydroxide   nesosilicate ,  Ca B Si O 4 (O H ). It was first observed by  Jens Esmark  in 1806, in allusion to the granular structure of the massive mineral. Datolite crystallizes in the  monoclinic  system forming prismatic  crystals  and nodular masses. The luster is vitreous and may be brown, yellow, light green or colorless.

13. FACT OF BORIC ACID DIFFERENT NAMES OF BORIC ACID Orthoboric acid, Hydrogen orthoborate , Boracic acid FORMULA OF BORIC ACID H3BO3 ELEMENTS OF BORIC ACID Hydrogen , boron, oxygen Compound Type of Boric Acid INORGANIC ACID Physical State od Boric Acid Solid

14. FACT OF BORIC ACID MOLECULAR WEIGHT OF BORIC ACID 61.83 g/ mol MELTING POINT OF BORIC ACID 170.9C (339.6F) BOILING POINT OF BORIC ACID Decomposes above its melting point SOLUBILITY OF BORIC ACID Soluble in water, ethyl alcohol, and glycerol TOXICITY OF BORIC ACID Boric acid is toxic if swallowed

15. METHODS OF PREPARING HYDROBROMIC ACID, PROPERTIES AND APPLICATIONS

16. What is Hydrobromic Acid? P owerful acid formed in water by dissolving bromides of hydrogen. Diatomic molecule with the chemical formula of HBr . Hydrogen bromide is a colorless, suffocating gas, very soluble in water and highly dissociated in aqueous solution. It readily fumes in the presence of moist air. Hydrogen bromide gas are highly corrosive substances that can cause severe burns upon contact . Other names – Hydrogen bromide, bromane

17. What is Hydrobromic Acid? HBr Hydrobromic Acid Density 1.49 g/cm³ Molecular Weight/ Molar Mass 80.9119 g/ mol Boiling Point 122 °C Melting Point -11 °C Chemical Formula HBr

18. Hydrobromic Acid Structure – HBr

19. Physical Properties of Hydrobromic Acid – HBr Odour Pungent irritating odor Appearance Colorless/faint yellow liquid Covalently-Bonded Unit 1 Heat capacity 29.1 J/( K·mol ) Hydrogen Bond Donor 1 Solubility Soluble in water

20. Chemical Properties of Hydrobromic Acid – HBr Hydrobromic acid reacts with sulfuric acid forming  sulfur dioxide , bromine and water. The chemical equation is given below . 2HBr + H 2 SO 4  → Br 2  + SO 2  + 2H 2 O Hydrobromic acid reacts with propene undergoe addition reaction resulting in the formation of 2-Bromopropane. The chemical equation is given below. HBr + C 3 H 6  → C 3 H 7 Br

21. Uses of Hydrobromic Acid – HBr Used as a chemical intermediate, the major uses for elemental bromine are as a sanitizing or disinfecting agent. Used as a reagent and as a catalyst in a variety of organic reactions. Used in the preparation of numerous  organic compounds . *Anhydrous hydrobromic acid is hazardous and shipped in high pressure cylinders.