Report Water Hardness

8/11/2019 Report Water Hardness

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EXPERIMENT

Water Hardness

OBJECTIVE

To learn the cause and the effects of hard water

To determine the total, Ca and Mg hardness of a water sample

INTRODUCTION

Water becomes hard by being in contact with soluble, divalent, metallic

cautions. The two main cautions that cause water hardness are calcium (Ca) and

magnesium (Mg). Calcium is dissolved in water as it passes over and through

limestone deposits. Magnesium is dissolved as water passes over and through

dolomite and other magnesium bearing formations. Because groundwater is in

contact with these geologic formations for a longer period of time than surface water,

groundwater is usually harder than surface water. Although strontium, aluminum,

barium, iron, manganese, and zinc also cause hardness in water, they are not

usually present in large enough concentrations to contribute significantly to total

hardness.

Hardness was originally defined as the capacity of water to precipitate soap.

Calcium and magnesium precipitate soap, forming a curd which causes “bathtub

ring” and dingy laundry (yellowing, graying, loss of brightness, and reduced life of

washable fabrics), and feels unpleasant on the skin (red, itchy, or dry skin). To

counteract these problems, synthetic detergents have been developed. These

detergents have additives known as sequestering agents that “tie-up” the hardness

ions so they cannot form the troublesome precipitates. Although synthetic detergents

overcome these problems, both soap and detergent are wasted by hardness.

Hard water forms scale, usually calcium carbonate, which causes a variety of

problems. Left to dry on the surface of glassware, silverware, and plumbing fixtures

(shower doors, faucets and sink tops), hard water leaves unsightly scale, called

water spots. Scale that forms on the inside of water pipes eventually reduces the



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water pipes‟ carrying capacity. Scale that forms within appliances, pumps, valves,

and water meters causes wear on moving parts.

When hard water is heated, scale forms much faster. This creates an

insulation problem inside boilers, water heaters, and hot-water lines and increases

heating costs.

MATERIALS AND APPARATUS

1. Chemicals and Solutions

a. Calcium and magnesium indicator solution (calmagite)

b. Alkali for calcium and magnesium test

c. EDTA solution

d. EGTA solution

e. 10 g/L slaked lime (Ca(OH)²) slurry solution

f. Water sample

2. Equipment and Glassware

a. Jar stirrer

b. Centrifugal

c. DR 2800 Spectrophotometer

d. 100 ml Volumetric flask

e. Pipette

f. 1000 ml beakers



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PROCEDURE

1. The water samples are obtained. The sample may simply the tap water in the

laboratory and from a river.

2. DR 2800 Spectrophotometer is switched on. Press STORED PROGRAMS

and the test is selected 225 hardness Mg.

3. The 150 ml of samples (tap water and stream water) are poured into a beakerto check the PH level.

4. Then, the 100 ml of the samples (tap water and stream water) are poured into

a volumetric flask.

5. Calcium and Magnesium Indicator solution (calmagite) is added in 1 ml using

1.0 ml measuring dropper or micropipette.

6. The volumetric flask is stopped and swirl it several times.

7. Alkali Solution for Calcium and Magnesium Test is added in 1 ml using a 1.0

ml measuring dropper or micropipette.

8. The volumetric flask is swirl for several times.

9. The square sample cells are cleaned up with ultrapure water.

10. The 10 ml of the solution is poured into each of three square sample cells.

11. Blank Preparation: A drop of EDTA solution is dropped to the first cell and

swirl to mix.



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12. Magnesium Sample: A drop of EGTA solution is dropped to the second cell

and swirl to mix.

13. Insert the blank (first cell) into the cell holder with the fill line facing right.

Press ZERO and the display showed 0.00 mg/l Mg CaCO³.

14. Insert the magnesium sample (second cell) into the cell holder with the fill line

facing right. Press READ. Results are in mg/l magnesium as calcium

carbonate (amount of magnesium in sample expressed as CaCO³).

15. Do not remove the cell from the instrument. Record the magnesium results

before proceeding with step 16.

16. Press MAIN MENU. Select the test again. Press SOURCE PROGRAM for

220 hardness Ca and press START.

17. Press ZERO. The display will show: 0.00 mg/l Ca CACO³. Remove the

second cell.

18. Calcium sample: Insert the third cell into the cell holder with the fill line facing

right. Press READ. Results are in mg/l calcium as calcium carbonate. This

value is the amount of calcium in the sample expressed as CaCO³.

RESULTS

Parameter Initial sample

Tap water River water

PH 7.55 7.63

Calcium hardness 0 0.34

Magnesium hardness 3.25 2.87

Total hardness 2.25 3.21



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DISCUSSION

Based on the experiment hard water is water that has high mineral content.

Hard drinking water is generally not harmful to one's health, but can pose serious

problems in industrial settings, where water hardness is monitored to avoid costly

breakdowns in boilers, cooling towers, and other equipment that handles water. In

domestic settings, hard water is often indicated by a lack of suds formation when

soap is agitated in water and by the formation of lime scale in kettles and water

heaters.

The experiment to determine the total of Calcium and Magnesium hardness of

the water samples (tap and river water). The result showed the differential hardness

reading between the water samples. The reading of the pH for tap water is 7.050 and

river water is 7.745. For the calcium hardness of the tap water is 0 and the river

water is 30 mg/l. Moreover, the magnesium hardness of the both samples is 2.16 fortap water and 21.6 mg/l for river water. Thus, the total of the tap water is 2.16 mg/l

and river water is 60.6 mg/l.

From the observation the result that is differential result for the both samples.

The differential the total hardness of the both samples are around 58.44 mg/l. The

result showed that the river water more hardness from the tap water. The river water

consist two mineral which is calcium and magnesium. Meanwhile the tap water just

consist magnesium and only 2.16 mg/l the magnesium mineral.

Nevertheless, the results of the river water have a problem which is the

machine (DR 2800 Spectrophotometer) can‟t read the reading of the river water

solution. Thus, the reading of the river water should do the dilution which is use in

ratio. The steps for the dilution which are pour 5 ml river water in the volumetric flask.

After that, added 100 ml ultra pure water and add 1 ml of Calcium and Magnesium

Indicator solution and 1 ml Alkali Solution. Swirl the solution and pour the solution

into the three square sample cells. Add 1 drop EDTA solution to the first cell and 1



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drop the EGTA solution to the second cell. Continue the procedure and read the

result for the river water. The ratio of the dilution process is 5:100 and become 1:20.

So, the river water results that get at the machine should times 20.

Although the both samples in classification of the soft water but the tap water

more soft because the tap water through the water treatment process. The river

water not through any process to became soft water. The river water also

contaminate with contaminated material like waste from factory, residential and so

on.

CONCLUSION

As the conclusion, the experiment showed that the softer than the river wateralthough the both of the water samples in the soft classification. Tap water in some

parts of the country is very pure and is said to be „soft‟. It easily makes lather with

soap. Water from other parts may contain various dissolved impurities and is

described as „hard‟ water. Temporary hardness may be removed by boiling, but

permanent hardness survives the boiling process.

The upshot is that hard water doesn't wash as well as soft water. Clothes and

sheets washed in hard water can feel rough, even harsh to the touch. Skin washed

in hard water is typically reported as feeling scratchy and dry as a result of the soap

scum, and hair is often reported as being dull-looking and sticky.

Nevertheless, the hard water is not interfere the citizen healthy because Hard

water can be problematic in terms of taste, colour, and deposits inside pipes and

plumbing and on cookware and appliances such as water heaters and dishwashers.

It's not generally considered a health hazard, though.

Thus, the water hardness water test can classify the several of water in the world.



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QUESTION

1. What are the problems associated with hardness in water.

The problems associated with hardness in water:

a. Laundering

Clothes washed in hard water often look dingy and feel harsh and

scratchy. The hardness minerals combine with some soils to form

insoluble salts, making them difficult to remove. Soil on clothes

can introduce even more hardness minerals into the wash water.

b. Bathing

Bathing with soap in hard water leaves a film of sticky soap curd on the

skin. The film may prevent removal of soil and bacteria. Soap curd interferes

with the return of skin to its normal, slightly acid condition, and may lead to

irritation. Soap curd on hair may make it dull, lifeless and difficult

to manage.

c. Dishwashers

When washing dishes, especially in a dishwasher, hard water may

cause spotting and filming on your crockery. The minerals from hard

water are released faster when it comes into contact with heat,

causing an increase in the amount of spotting and filming that occurs. This



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problem is not a health risk, but it can be a nuisance to clean and

reduce the quality of your crockery.

2. What are the benefits of using soft water?

a. Having soft water saves the money. When the water is soft, use much

less soap and fewer cleaning products. The budget will automatically

reflect the savings.

b. The plumbing will last longer. Hard water can cause a build up of scale

from mineral deposits. Over time, pipes can clog, water flow can diminish,

and water pressure can be reduced. This doesn't happen with soft

water. Soft water is low in mineral content and therefore doesn't leave

deposits in the pipes.

c. The hot water heater will last longer. Scale and lime build-up created

by minerals will not take place if the water is soft. This adds life to

the hot water heater. Also, if don't have deposits in hot water heater, it

will cost approximately 20% less to heat the water that

consumer does use. At the end of a year, these savings can really add up.

d. Diminished razor burn: Soft water causes the razor to glide more easily

across the face. This, in turn, causes the razor blades to last longer.



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e. Most water-using appliances will last longer. Whether it's coffee pot,

humidifier, or hot tub, soft water inhibits a build-up of minerals

and adds life to these products.

3. Give the advantages of using lime softening in water treatment.

The disadvantages of the lime softening in water treatment which is proper

disposal of the large quantity of high pH sludge; constant removal of the calcium

carbonate scale on slaking equipment, rapid mixers, and flocculation basin

equipment; safety issues regarding dosing sodium hydroxide or soda ash, and the

slaking and feeding of lime. Extreme care must be taken when working arounddry lime (CaO). The addition of water generates a lot of heat. One must never

apply water from a hose directly to a dry lime spill or accumulation in a

slacker, as there exists the potential of explosion resulting from escaping gases

in heat from the interior of the lime pile.

REFERENCES

1. http://wiki.answers.com/Q/What_are_problems_associated_with_hard_water

2. http://www.hardwater.org/hard_water_problems.html

3. http://en.wikipedia.org/wiki/Hard_water

http://wiki.answers.com/Q/What_are_problems_associated_with_hard_water

http://www.hardwater.org/hard_water_problems.html

http://en.wikipedia.org/wiki/Hard_water

http://en.wikipedia.org/wiki/Hard_water

http://www.hardwater.org/hard_water_problems.html

http://wiki.answers.com/Q/What_are_problems_associated_with_hard_water

Documents

Report Water Hardness