G4 planning lab

Shaping of green bricks is done using four techniques, classified on the basis of water content in raw-mix, as given below:

Of these, the extrusion and wire cutting technique is most widely used all over the developed world while soft-mud molding is practiced in most developing countries and in countries like, the Netherlands. Majority of brick makers in India practice hand-molding technique only. Semi-dry pressing or dust pressing is used for manufacturing facia bricks and decorative flat products. Dry pressing, though considered technically feasible, is not a viable technique for making ordinary fired clay bricks in most places due to its ‘high-volume-low-margin’ nature.

Materials Required:

1. Water sample in an air-tight container of the drinking water to be studied;
   
2. Apparatus for testing the pH of the sample:

• pH strips; and
• Colour scale.
  

3. Apparatus for testing the dissolved oxygen content of the sample:

• Measuring cylinders

• Corks.

• Burette (for titration);

• conical flask;
•  graduated test tubes;
• Manganese salt (Manganese Chloride);
•  Potassium Iodide + Potassium Hydroxide solution;
•  Sodium Thiosulphate solution;
•  Starch indicator solution, Conc. Hydrochloric acid;

4. Apparatus for testing the chloride content of the sample:

• 10 cm2 pipette;
•  Burette;
•  distilled water in a wash bottle;
•  3 C flasks, white tile;
•  potassium chromate indicator;
•  50 cm3 silver nitrate solution.

Procedure: 

1. DISSOLVED OXYGEN CONTENT:

The dissolved oxygen content can be found out using the Winkler’s method. This method is from the point of view of chemistry students.

The Winkler test is used to determine the concentration of dissolved  in water samples. Dissolved Oxygen, abbreviated D.O., is widely used in water quality studies and routine operation of water reclamation facilities. An excess of Manganese(II) salt, iodide (I-) and hydroxide (OH-) ions are added to a water sample causing a white precipitate of Mn(OH)2 to form. This precipitate is then oxidized by the dissolved oxygen in the water sample into a brown  precipitate. In the next step, a strong acid (either hydrochloric acid or sulphuric acid) is added to acidify the solution. The brown precipitate then convert the iodide ion (I-) to . The amount of dissolved oxygen is directly proportional to the titration of Iodine with a  solution.

2 Mn(OH)2(s) + O2(aq) → 2 MnO(OH)2(s)

4 Mn(OH)2(s) + O2(aq) + 2 H2O → 4 Mn(OH)3(s)

Mn(SO4)2 + 2 I-(aq) → Mn2+(aq) + I2(aq) + 2 SO42-(aq)

2 S2O32-(aq) + I2 → S4O62-(aq) + 2 I-(aq)

2. pH OF WATER SAMPLE:

The pH of water sample can be found out by using the pH strips and then the colour can be matched with the colour chart and the pH can be found out.

3. CHLORINE CONTENT IN WATER SAMPLE:

1. Place 10cm3 of water sample into a conical flask and add 4 drops of potassium chromate indicator solution.
2. Titrate silver nitrate solution from the burette, shaking the conical flask constantly.
3. The end-point of the titration is given by a reddening of the silver chloride precipitate.
4. Repeat the titration on a further two 10 cm3 water samples. Calculate the mean volume of silver nitrate used.
5. The volume of silver nitrate solution used is approximately equal to the chloride content of the water sample (in g dm3).

DATA COLLECTION-

1) Table 1.1: DISSOLVED OXYGEN CONTENT IN THE WATER SAMPLE:

• Water sample being tested: Original drinking water sample taken from the tube well near the brick kiln.
• Amount of water sample taken: 10 ml.

• Note: The solubility of oxygen increases with a decrease in temperature.

2. Table 1.2: pH OF WATER SAMPLE:

• NOTE:
  Rapids growing algae remove carbon dioxide from the water during photosynthesis, which can result in a significant increase in pH levels.

3. Table 1.3: CHLORIDE CONTENT OF WATER SAMPLE:

Conclusion: According to the readings I have got by conducting the experiment, I think that the water in the well in contaminated and is not fit for drinking seeing the observations and result and it can be said that by consuming this water the people at the brick kiln can be affected by diseases.