Eriochrome Black TS

Eriochrome Black is use in testing the hardness of water as well as testing of the Calcium and Magnesium serving as indicator. 

To prepare the solution, 

Dissolve 200 mg of eriochrome black T and 2 g of hydroxylamine hydrochloride in methanol to make 50 mL.

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How to Prepare Boric Acid and Potassium Chloride, 0.2 M

Dissolve 12.37 g of boric acid (H3BO3) and 14.91 g of potassium chloride (KCl) in distilled or deionized  water, and dilute with Deionized water to 1000 mL.

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How to Prepare Ammonium Thiocyanate, 0.1 N

NH4SCN, 76.12

7.612 g in 1000 mL

Dissolve about 8 g of ammonium thiocyanate in 1000 mL of water, and standardize the solution as follows.

Accurately measure about 30 mL of 0.1 N silver nitrate VS into a glass-stoppered flask. Dilute with 50 mL of water, then add 2 mL of nitric acid and 2 mL of ferric ammonium sulfate TS, and titrate with the ammonium thiocyanate solution to the first appearance of a red-brown color. 

If desirable, 0.1 N ammonium thiocyanate may be replaced by 0.1 N potassium thiocyanate where the former is directed in various tests and assays.

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How to Prepare Acetic Acid, 2N

Acetic acid
Chemical Compound
Acetic acid /əˈsiːtᵻk/, systematically named ethanoic acid /ˌɛθəˈnoʊᵻk/, is an organic compound with the chemical formula CH₃COOH. It is a colourless liquid that when undiluted is also called glacial acetic acid.Wikipedia
Formula: CH₃COOH
Molar mass: 60.05 g/mol
Density: 1.05 g/cm³
Boiling point: 118 °C
IUPAC ID: Acetic acid
Melting point: 16 °C

C2H4O2, 60.05

If solid, add 120.10 g of Acetic Acid in 1000 mL of water to produce 2N Acetic Acid

If acid in a liquid form, 

Add 116 mL of glacial acetic acid to sufficient water to make 1000 mL after cooling to room temperature.

Please be careful in handling and preparing acids. Wear gloves, goggles and safety devices as necessary. 

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How to Test for Hard Water

You can do a fairly reliable unscientific test to see if you have a problematic level of hard water in your home by doing the following test with liquid dish washing soap:

Take a clean empty plastic bottle having a cap (such as a clean, clear pop bottle);

Remove the cap;

Open your tap water faucet and fill the bottle with about a half-cup of water (8 to 10 ounces);

Add 10 drops of dish washing liquid;

Shake well;

If the soapy solution foams up quickly you are good and the water is not hard;

If it does not foam up but instead creates a milk-curd-like or soapy film on the water surface then the water is likely hard.

If you have hard water scale build-up on your shower door or white scale on your faucet aerator, this is also another indicator your water is too hard.

You can also send a water sample out for testing to a certified water testing laboratory. Hard water is anything above 1 grain of hardness per gallon. (A grain of hardness is an amount of calcium and magnesium equal in weight to a kernel of wheat).

• Less than 1.0 = Soft
• 1.0 - 3.5 = Slightly Hard
• 3.5 - 7.0 = Moderately Hard
• 7.0 - 10.5 = Hard
• Over 10.5 = Very Hard

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