Chemicals In Our Daily Life

When hydrochloric acid (HCl) is added to potassium permanganate (MnO₂) then chlorine gas is formed.

MnO₂ + 4HCl→MnCl₂ + Cl₂ + H₂O

On another hand Zn and HCl form Zinc chloride (ZnCl₂).

CaCO₃ and HCl form calcium chloride (CaCl₂).

Pb(NO₃)₂ and HCl form Lead chloride (PbCl₂).

The chief sources of oils used to make soap are animals and plants.

On small scale oil, sodium hydroxide and common salt are used to make soap. Oil and sodium hydroxide is heated in the kettle then soap and glycerine are formed, Salt is added to separate soap from glycerin.

Oil/fat + sodium hydroxide→soap + glycerin

Detergents are made using petroleum products.

1. MnO₂ + 4HCl → MnCl₂ + Cl₂ + H₂O

When manganese dioxide is heated with concentrated hydrochloric acid, then a greenish yellow gas is liberated which is called chlorine (Cl₂) and manganese chloride and water is also formed along with chlorine. Chlorine has various applications in our industry.

2. Common name of sodium chloride (NaCl) is ‘common salt’ or ‘Table salt’. Sodium and Chlorine react together to give sodium chloride. Its chemical equation is given below:

2Na + Cl₂→2NaCl

Common salt gives taste to our food. Sodium chloride is the salt most responsible for the salinity of seawater.

3. Chemical name of baking soda is sodium bicarbonate (NaHCO₃).

Baking soda is made by passing carbon dioxide (CO₂) through sodium carbonate solution (Na₂CO₃) in water (H₂O).

Na₂CO₃ + H₂O + CO₂→2 NaHCO₃

Baking soda is used to make a baking powder which is while cooking something or in bakery items, Baking Soda is also used in medicine as an antacid.

The gases which are made by chemical reactions are collected in different ways depending on their density. If the gas produced is less dense than the air, then the air goes at the bottom of the test tube since air is denser than gas and the gas occupies space at the top of test tube so downward displacement of air takes place.

On another hand if the gas produced is denser than the air, then the gas occupies space at the bottom of the test tube and air goes at the top of the test tube and, i.e. upward displacement of air takes place.

Since chlorine is denser than air, so it is collected in the test tube or jar by upward displacement of air.

1. Chloroform is a compound of chlorine which is used as an anesthetic. Anesthetic is a drug by which person does not feel pain during surgery or operation. The chemical formula of chloroform is CHCl₃ and it is colorless. Nowadays it is very less used as an anesthetic as because its effects on the body can be serious, resulting in damage to both the liver and the kidneys.

2. chlorofluorocarbons (CFC) are a compound of chlorine which is used as a refrigerant. A refrigerant is a substance/fluid used in refrigerators or heat pump. CFC has some harmful effects on the environment as it leads to global warming and ozone layer depletion.

3. Sodium hypochlorite (NaoCl) and Calcium hypochlorite are used as a disinfectant. Disinfectant is a chemical which kills the bacteria or microorganisms. Sodium hypochlorite is a yellowish liquid and using sodium hypochlorite, disinfection is achieved at low concentrations of chlorine in water and sodium has no effect on water. Calcium hypochlorite is available as white powder or tablets so it is dissolved in warm water.

4. PVC (polyvinyl chloride) is a chlorine compound used to make

pipes and tubes. Chlorine and ethylene gas react together to form vinyl chloride at high temperature then vinyl chloride forms PVC by polymerization. In polymerization small molecules (vinyl chloride) join together to make very long molecules like PVC.

5. Bleaching Powder liberates chlorine on exposure to air. Its chemical formula is calcium oxy-chloride (CaOCl₂) and it is a yellowish powder. When bleaching powder is exposed to air, it reacts with carbon dioxide of surrounding to form chlorine gas and calcium carbonate. Its chemical equation is:

CaOCl₂ + CO₂→ CaCO₃ + Cl₂

There are several uses of chlorine; some of them are listed below:

● Chlorine is used to manufacture Bleaching powder when chlorine gas is passed into calcium hydroxide, bleaching powder is formed. It is used for whitening dirty clothes in the laundry and disinfecting drinking water.

● Chlorine used in the preparation of pesticides like benzene hexachloride commonly (BHC) and DDT. These pesticides are used to kill harmful insects or pests that attack crops in agriculture.

● Chlorine is used to make common salt which is a very important component used in food, labs and in industry.

● Chlorine is used to make chloroform that has medical application as anesthetics and chlorine also helps in making of pipes by PVC.

Copper metal (Cu) and concentrated sulphuric acid (H₂SO₄) are required to prepare sulphur dioxide (SO₂) in the laboratory.

5g of copper pieces is taken in a flask and 10 ml sulphuric acid is added to it, the flask is heated and sulphur dioxide is formed. It is collected in a jar by upward displacement of air.

Cu + H₂SO₄⇒ CuSO₄ + SO₂ + H₂O

Sulphur dioxide dissolves in water to give sulphurous acid.

The chemical equation for acid formation: SO₂ + H₂O → H₂SO₃

Also, water from rain reacts with sulphur dioxide to produce acid rain. Acid rain decreases the fertility of soil, it also corrodes buildings and monuments, and its harmful to aquatic life. Sulphurous acid are used as disinfecting agents.

Uses of sulphur dioxide are listed below:

● In industry, sulphur dioxide is used to remove coloring matter from sugar hence acts as bleaching agent and it is also used as a preservative i.e. it maintains the colorful appearance of fruits (especially dry fruits) and prevents them from rotting.

● It is widely used for manufacturing sulphuric acid by contact process, it can be also used as a refrigerant in refrigerators and as a solvent in laboratories.

Difference between soap and detergent are:

● Soaps are made from animal or plants fats or oils so they are biodegradable but Detergent are manufactured from petroleum products hence less biodegradable.

● Soap does not give lather with hard water so they have lesser cleansing action but detergents work well with soft as well as hard water so they have better cleansing action than soaps.

Detergents were first made in Germany. In industries, long chains of hydrocarbon from petroleum are reacted with concentrated sulphuric acid (H₂SO₄), then the intermediate product formed is neutralized with sodium hydroxide (NaOH) and the detergent is formed. Detergents are mainly available as powders or concentrated solutions.

Detergents are of three types:

● Cationic detergent

● Anionic detergent

● Non-ionic detergent

Note: Hydrocarbon is a chemical compound containing hydrogen and carbon.

Hydrocarbon + H₂SO₄ → Intermediate product

Intermediate product + NaOH → Detergent

Soap is one of the most common cleansing agents but they are capable of cleaning dirt only in soft water, soap does not form lather with hard water and therefore cleansing action does not become effective but detergents can clean dirt in hard as well as soft water with same effectiveness because detergent forms lather with hard water along with soft water, hence detergent is better than soap in cleaning action.

purification of water takes place in several steps in water treatment plant:

Screening: when the water source is a lake or river, large contaminants such as plants, polythene or fish are removed.

Coagulation: chemicals are added to attract dirt particles and make them sink to the bottom of the tank.

Sedimentation: As water becomes still, these dirt particles are removed.

Filtration: water passes through several layers of charcoal to filter out remaining particles.

Disinfection: water goes in a tank and chlorine or other disinfecting chemicals are added to it to kill bacteria.