Chemistry Project

CHEMISTRY PROJECT NAME: AZAD ABDULLAHI CLASS: SS3S TEACHER: MR. ADEKUNLE

CONTENTS 1. SODIUM COMPOUNDS a. b. c. d.

NaOH i)Preparations ii )properties/reactions iii)Uses NaCl i)Preparations ii )properties/reactions iii)Uses Na2CO3 i)Preparations ii )properties/reactions iii)Uses NaOCl i)Preparations ii )properties/reactions iii)Uses

2. CALCIUM COMPOUNDS e. f. g. h.

Ca(OH)2 i)Preparations ii )properties/reactions iii)Uses CaCl2 i)Preparations ii )properties/reactions iii)Uses CaCO3 i)Preparations ii )properties/reactions iii)Uses Ca(HCO3)2 i)Preparations ii )properties/reactions iii)Uses

3. CALCIUM COMPOUNDS i. j. k. l.

Al(OH)3 i)Preparations ii )properties/reactions iii)Uses AlCl3 i)Preparations ii )properties/reactions iii)Uses Al2O3 i)Preparations ii )properties/reactions iii)Uses NaOCl i)Preparations ii )properties/reactions iii)Uses

SODIUM COMPOUNDS NaOH PREPARATION Sodium hydroxide, NaOH, commonly known as caustic soda, is industrially manufactured by the electrolysis of brine. In the Laboratory, it is prepared by heating an excess of slaked lime with 10% sodium trioxocarbonate (IV) solution. The insoluble trioxocarbonate (IV) that is formed is filtered off, leaving behind a solution of sodium hydroxide, which is concentrated by evaporation. Na2CO3 (aq) + Ca(OH) 2 (S)

CaCO3 (s) + 2NaOH(aq)

PROPERTIES 1. sodium hydroxide is a white crystalline solid. Its crystals deliquesce when exposed in air to form sodium hydroxide solution 2. It readily dissolves in water with evolution of heat, giving a strong alkaline solution. It is also soluble in ethanol. 3. Sodium hydroxide solution, as a strong alkali, turns red litmus paper to blue. 4. it is a typical base, neutralizing all acids however weak to form the appropriate salt and water 5. sodium hydroxide when exposed readily absorbs carbon (IV) oxide, a weak acidic oxide, to form disodium trioxocarbonate (IV). 6. Sodium hydroxide reacts with a variety of non-metals such as halogens, silicon and phosphorous to form sodium salts USES 1. 2. 3. 4. 5. 6.

as a strong alkali in the neutralization of acids to form mineral salts as an analytical agent used in the manufacture of soap used in the refining of petroleum used In the manufacture of paper for absorbing carbon (IV) oxide gas

NaCl PREPARATION Sodium Chloride is found in some areas as rock salt which can be mined as a solid or pumped out of the ground as brine. It can also be obtained by the solar evaporation of sea water. In the laboratory, sodium hydroxide is formed by the neutralization of sodium hydroxide and dilute hydrochloric acid NaOH (aq) + HCl (aq)

NaCl (aq) + H 2O (l)

PROPERTIES 1. Sodium Chloride forms white anhydrous crystals which melt at 801 degrees Celsius and boil at 1420 degrees Celsius. 2. pure sodium chloride is not deliquescent but the impure salt may be, due to the presence of magnesium chloride USES 1. it is an essential part of our diet 2. it is sometimes used as a food preservative 3. it is used in the manufacture of sodium, sodium hydroxide, chlorine and other related compounds 4. it is used in glazing earthenware 5. salting our soap

Na 2CO 3 PREPARATION Ammonia and carbon dioxide are passed into a saturated sodium chloride solution to form soluble ammonium hydrogen carbonate, which reacts with the sodium chloride to form soluble ammonium chloride and a precipitate of sodium hydrogen carbonate (sodium bicarbonate) if the temperature is maintained below 15°C. The sodium hydrogen carbonate is filtered off and heated to produce sodium carbonate. The process used for commercial purposes is called SOLVAY PROCESS or ammonia soda process. The materials involved are brine, carbon dioxide and ammonia gas. The sodium chloride solution reacts with ammonia gas to give ammoniacal brine (NaCl + NH 3 m water.) As the process continues, the ammonia reacts with carbon (IV) oxide to give ammonium hydrogen trioxo carbonate (IV) CaCO3

CaO + CO2

NH3 + CO2 + H2O

NH4 HCO3

this is the presence of sodium chloride solution forms a white precipitate of sodium hydrogen trioxo carbonate (IV) NH4 HCO3 + NaCl

Na HCO3 + NH4Cl

Sodium hydrogen trioxo carbonate (IV) which is not soluble in NaCl solution is filtered and heated to produce anhydrous disodium trioxo carbonate (IV). 2NaHCO3 Na2CO3 + H2O + CO2 This is later crystallized in hot water to produce washing soda. Na2CO3 + 10 H2O

Na2CO3 *10 H2O

Hydrated trioxo carbonate (IV) (washing soda) PROPERTIES 1. it is efflorescent by loosing its water of crystallization 2. it does not decompose on heating 3. it reacts with acid to liberate carbon (IV) oxide.

Uses

•

•

• • • •

•

Glass making: More than half the sodium carbonate is used to make glass. Bottle and window glass is made by melting a mixture of sodium carbonate, calcium carbonate and sand (silicon dioxide). Water treatment: Sodium carbonate is used to soften water (precipitates out Mg2+ and Ca2+ carbonates). This is used both industrially and domestically (in some washing powders). Making soaps and detergents: Often sodium carbonate is used as a cheaper alternative to sodium hydroxide. Paper making: Sodium carbonate is used to make sodium hydrogen sulphite (NaHSO3) for the "sulphite" method of separating lignin from cellulose. As a common base in many chemical factories because it is cheaper than NaOH. Making sodium hydrogen carbonate: NaHCO3 is used in baking soda and fire extinguishers. Though NaHCO3 is produced in the Solvay process, heating it to remove the ammonia it is contaminated with decomposes some NaHCO3, so it is actually cheaper to react the finished Na2CO3 product with CO2. Removing sulfur dioxide from flue gases in power stations. This is becoming more common, especially overseas where stations have to meet stringent emission controls.

Differences between NaHCO3 & Na2CO3 1. NaHCO3 decomposes on heating to liberate CO2 while Na2CO3 does not. 2. Na 2CO3 forms a white precipitate with MgSO 4 while NaHCO3 cannot.

NaOCl

Preparation Sodium hypochlorite may be prepared by absorbing chlorine gas in cold sodium hydroxide solution: 2NaOH + Cl2 ⇌ NaCl + NaOCl + H2O Sodium hydroxide and chlorine are commercially produced by the chloralkali process, and there is no need to isolate them to prepare sodium hypochlorite. Hence NaOCl is prepared industrially by the electrolysis of sodium chloride solution without any separation between the anode and the cathode. The solution must be kept below 40 °C (by cooling coils) to prevent the formation of sodium chlorate. The commercial solutions always contain significant amounts of sodium chloride (common salt) as the main byproduct, as seen in the equation above. Note: A chloralkali process is any which produces chlorine or a related oxidizer, such as bleaching powder and an alkaline salt such as sodium hydroxide or sodium carbonate. Electrolysis of an aqueous solution of sodium chloride produces chlorine and sodium hydroxide: 2 NaCl(aq) + 2 H2O(l) —→ 2 NaOH(aq) + Cl2(g) + 2 H+ + 2 e-; 2 H+ + 2 e- —→ H2 (g). In the membrane cell, the anode and cathode are separated by an ion-permeable membrane. Saturated brine is fed to the compartment with the anode (the anolyte). A DC current is passed through the cell and the NaCl splits into its constituent components. The membrane passes Na+ ions to the cathode compartment (catholyte), where it forms sodium hydroxide in solution. The chloride ions are oxidised to chlorine gas at the anode, which is collected, purified and stored. Hydrogen gas and Hydroxide ions are formed at the cathode.

*Reactivity This solution is a reasonably strong oxidizing agent and reacts vigorously with reducing agents. Both with ammonia and

with amines the solution forms explosive, toxic chloramines. Solid NaOCl decomposes violently if heated or subjected to friction. USES 1. it can be used as a bleach 2. it is a global water disinfectant 3. Sodium hypochlorite solutions often contain other agents, including sodium hydroxide to maintain a pH-dependent equilibrium between hypochlorite and chlorine.

SOLVAY PROCESS DIAGRAM

CALCIUM COMPOUNDS

Ca(OH) 2 (slaked lime)

Preparation Industrially calcium hydroxide is obtained by the action of water on calcium oxide (CaO). The calcium oxide is prepared by roasting limestone. CaCO3 limestone

CaO + CO2 calcium oxide

In the laboratory it is prepared by adding sodium hydroxide solution to a solution of any soluble salt of calcium. e.g. calcium chloride 2NaOH + CaCl 2

Ca(OH) 2 + 2NaCl

Properties 1. calcium hydroxide is a white powder which dissolves slightly in water to give an alkaline solution of lime water 2. it neutralizes acids to give salt and water Ca(OH) 2

480oC

CaO + H 2O

3. it librates ammonia from ammonium salts Ca(OH) 2 + 2NH4Cl

CaCl 2 + NH 3 + 2H 2 O

4. calcium hydroxide decomposers at 480 o C to give calcium oxide and water Ca(OH) 2

CaO + H 2O

Uses 1. it is used in the production of bleaching powder

2. 3. 4. 5. 6. 7.

temporary hard water is softened by the addition of calcium hydroxide it is also used in the manufacture of glass used in the purification of coal gas and sugar used in the recovery of ammonia from ammonium chloride in the solvay process used in agriculture to neutralize acidic soil a suspension of calcium hydroxide in water (lime water) is used as a test for CO 2 in the laboratory

Calcium Chloride Laboratory Preparation

It is prepared in the laboratory by the action of dilute hydrochloric acid on calcium trioxocarbonate (IV). CaCO3 + 2HCl

CaCl 2 + H 2O + CO 2

Properties 1. The anhydrous form of calcium chloride is a white powder. 2. it has the typical reaction of a chloride 3. it is very deliquescent absorbing moisture from the air to form hydrated calcium chloride CaCl 2 + 5H 2O

CaCl 2 ` 5H 2O

Uses Because of the certain properties calcium chloride has , It is mainly used as a drying agent.

CaCO3

Preparation

it occurs abundantly in the earths crust as limestone, marble, chalk. It is also found in egg shells and sea shells. Laboratory Preparation Pure calcium trioxocarbonate can be prepared by double decomposition. E.g. Na 2CO 3 + CaCl 2

CaCO 3 + 2NaCl

It is obtained as a white solid It is also produced when CO2 is passed for a short time into lime water. Ca(OH) 2 + CO2

CaCO3 + H2O

Properties Calcium carbonate shares the typical properties of other carbonates. Notably: 1. it reacts with strong acids, releasing carbon dioxide. CaCO3 + 2HCl → CaCl2 + CO2 + H2O 1. it releases carbon dioxide on heating (to above 825 °C in the case of CaCO3), to form calcium oxide, commonly called burnt lime. CaCO3 → CaO + CO2 Calcium carbonate will react with water that is saturated with carbon dioxide to form the soluble calcium bicarbonate. CaCO3 + CO2 + H2O → Ca(HCO3)2 This reaction is important in the erosion of carbonate rocks, forming caverns, and leads to hard water in many regions.

Uses

The main use of calcium carbonate is in the construction industry, either as a building material in its own right (e.g. marble) or limestone aggregate for roadbuilding or as an ingredient of cement or as the starting material for the preparation of builder's lime by burning in a kiln . A common contaminate is magnesium carbonate. Calcium carbonate is widely used as an extender in paints, in particular matte emulsion paint where typically 30% by weight of the paint is either chalk or marble. Calcium carbonate is also widely used as a filler in plastics. Some typical examples include around 15 to 20% loading of chalk in uPVC drain pipe, 5 to 15% loading of stearate coated chalk or marble in uPVC window profile. Fine ground calcium carbonate is an essential ingredient in the microporous film used in babies nappies and some building films as the pores are nucleated around the calcium carbonate particles during the manufacture of the film by biaxial stretching. Calcium carbonate is also used in a wide range of trade and DIY adhesives, sealants and decorating fillers. Ceramic tile adhesives typically contain 70 to 80% limestone. Decorating crack fillers contain similar levels of marble or dolomite. It is also mixed with putty in setting Stained glass windows, and as a resist to prevent glass from sticking to kiln shelves when firing glazes and paints at high temperature. Calcium carbonate is widely used medicinally as an inexpensive dietary calcium supplement(1), antacid, and/or phosphate binder. It is also used in the pharmaceutical industry as a base material for tablets of other pharmaceuticals. Calcium carbonate is known as whiting in ceramics/glazing applications, where it is used as a common ingredient for many glazes in its white powdered form. When a glaze containing this material is fired in a kiln, the whiting acts as a flux material in the glaze. It is commonly called chalk as it has been a major component of blackboard chalk. Chalk may consist of either calcium carbonate or gypsum, hydrated calcium sulfate CaSO4·2H2O. As a food additive, it is used in some soy milk products as a source of dietary calcium.

Calcium bicarbonate (Ca(HCO3)2), also called calcium hydrogencarbonate, is a compound which exists only in solution. If a solution evaporates, the following reaction occurs: Ca(HCO3)2(aq) → CO2(g) + H2O(l) + CaCO3(s). Calcium bicarbonate is formed when water containing carbon dioxide in solution (also known as carbonic acid) reacts with calcium carbonate The reaction is very temperature sensitive, with a rise in temperature easily driving carbon dioxide out of the calcium bicarbonate solution. Calcium Bicarbonate [Ca (HCO3) 2] - Forms when water containing CO2 comes in contact with limestone. Also causes alkalinity in water. When heated CO. is released and the calcium bicarbonate reverts back to calcium carbonate thus forming scale.

Properties a bicarbonate that is a major cause of hard water

Uses utilized in paper conservation for washing treatments.