Production of various solutions and reagents


Caution when diluting acids and akalies! The dilution of acids/alkalies is often exothermic, due to intense heating up acids/alkalies can spray. If not otherwise indicated, always pour acids/alkalies into water, the latter in excess acts as a coolant. When working with caustic substances always wear protective goggles!

Solutions and reagents are as a rule to be prepared with distilled water.

The formulas can basically be used for larger or smaller quantities as long as the proportions are preserved.

Solutions and reagents are to be properly labeled. If necessary the danger symbols are to be applied.

The dissolving of solid substances can be generally accelerated by stirring or shaking(caution) or in cases where this does not help through a mild warming in a water bath.


Information concerning hazardous substances

Ammonia solution 25 % GSATZEND.gif (935 Byte)GSUMWELT.gif (758 Byte)  N    R 24-50     S (1/2)-26-36/37/29-45-61

Barium hydroxide (or octahydrate) GSATZEND.gif (935 Byte) C    R 20/22-34     S 26-36/37/38-45

Calcium oxide  GSGESUND.gif (476 Byte) Xi    R 41     S 22-24-26-39

Fuchsin   GSGESUND.gif (476 Byte) Xn   R 40    S 36/37

Hydrochloric acid 30-33 %  GSATZEND.gif (935 Byte) C    R 34-37     S (1/2)-26-45

Iodine  GSGESUND.gif (476 Byte) Xn  GSUMWELT.gif (758 Byte)  N   R 20/21-50    S (2)-23-25-61

Methanol GSLEICHT.gif (932 Byte) F GSGiftig.gif (734 Byte) T     R 11-23/25    S (1/2)-7-16-24-45

Nitric acid 65 % GSATZEND.gif (935 Byte) C    R 35     S (1/2)-23-26-27

Potassium dichromate GSGiftig.gif (734 Byte) T+ GSUMWELT.gif (758 Byte)  N   R 21-25-26-37/38-41-43-46-49-50/53    S 45-53-60-61

Potassium permanganate GSBRANDF.gif (891 Byte) O GSGESUND.gif (476 Byte) Xn  GSUMWELT.gif (758 Byte)  N   R 8-22-50/53

Silver nitrate  GSATZEND.gif (935 Byte)GSUMWELT.gif (758 Byte)  N    R 34-50/53     S(1/2)-26-45-60-61

Sodium hydroxide  GSATZEND.gif (935 Byte) C    R 35    S (1/2)-26-37/39-45

Sodium hydrogen sulphite solution 38 % GSGESUND.gif (476 Byte) Xn    R 22-31     S (2)-25-46

Sodium nitrite GSBRANDF.gif (891 Byte) O GSGiftig.gif (734 Byte) T GSUMWELT.gif (758 Byte)  N    R 8-25-50     S (1/2)-45-61

Sulfuric acid 96 %  GSATZEND.gif (935 Byte) C    R 35   S (1/2)-26-30-45


Acids

Hydrochloric acid ca. 7 % (diluted ~)

20 ml Hydrochloric acid 30-33 % into 75 ml water.

Nitric acid 13 % (diluted ~) GSATZEND.gif (935 Byte) C    R 34     S (1/2)-23-26-27

10 ml nitric acid 65 % into 60 ml water.

Sulfuric acid 10 % (diluted ~) GSGESUND.gif (476 Byte) Xi   R 36/38    S (1/2)-26-30-45

25 ml sulfuric acid 96 % carefully into 398 ml water. Not vice versa!


Alkalies

Ammonia solution 3.5 % (diluted ~)

10 ml Ammonia solution 25 % into 55 ml water.

Sodium hydroxide solution 7.5 % (verdŁnnte ~)  GSATZEND.gif (935 Byte) C    R 35     S (1/2)-26-37/39-45

15 g Sodium hydroxide (biscuits or beads are preferable) into 185 ml water.

Sodium hydroxide solution 20 % (half concentrated ~) GSATZEND.gif (935 Byte) C    R 35     S (1/2)-26-37/39-45

15 g Sodium hydroxide (biscuits or beads are preferable) into 60 ml water. Not vice versa, strong heating up!

Sodium hydroxide solution 33 % (concentrated ~)  GSATZEND.gif (935 Byte) C    R 35     S (1/2)-26-37/39-45

33 g Sodium hydroxide (biscuits or beads are preferable) into 77 ml water. Not vice versa, strong heating up!


Detection reagents

Barium hydroxide solution    GSGESUND.gif (476 Byte) Xn     R20/22

2 g Barium hydroxide (octahydrate) into 50 ml water in a closed botte and shake. Filter out the deposit and store airtight.

Bromine water

See Demonstration of bromine

Ceric ammonium nitrate nitric acid solution

According to Prof. Blume (German)

2,4-Dinitrophenylhydrazine-reagent

Dissolve via heating and stirring 1 g 2,4-dinitrophenylhydrazine (in case of damp substances correspondingly more) into 25 ml 75 - 85 % phosphoric acid. Let cool and filter out deposits if present. Add 25 ml isopropanol or ketone-free ethanol or denatured alcohol.

Fuchsin sulphuric acid(Schiff's reagent) GSGESUND.gif (476 Byte) Xi     R 36/37/38    S 26-36

Dissolve 0,5 g fuchsin in 250 ml water, add 10 ml sodium hydrogen sulphite solution 38 %. After about 10 minutes add 10 ml concentrated hydrochloric acid. Before using let stand for at least 1-2 hours.

Can be purchased as a finished product at Omikron GmbH.

Iodine-potassium iodide solution

Dissolve 2 g potassium iodide in 4 ml water, mix with 1 g Iod, after disolving fill with water to 300 ml.

Potassium iodide starch solution

Prepare a paste of 1 g starch adding water drop by drop while stirring, then while stirring add 100 ml boiling water. Add 0.5 g potassium iodide.

Potassium manganate solution, diluted

Dissolve 1 g potassium mangante in 100 ml water.

Lime water

Add 1 g calcium oxide (burnt lime) to 500 ml water in a closed bottle and shake. Filter out the deposit and store airtight.

Sodium nitrite solution, diluted  GSGESUND.gif (476 Byte) Xn GSUMWELT.gif (758 Byte)  N    R 8-25-50     S (1/2)-45-61

Dissolve 1 g sodium nitrite in 25 ml water.

Sulphuric acid potassium dichromate solution GSGiftig.gif (734 Byte) T+ GSATZEND.gif (935 Byte) C GSUMWELT.gif (758 Byte)  N R 21-25-26-35-37/38-41-43-46-49-50/53    S (1/2)-26-45-53-60-61

Dissolve 4.0 g potassium dichromate (caution when weighing and filling!) in 20 ml distilled water (preferably lukewarm). This can take some time, perhaps sway and let stay several times. Carefully add divided into two portions (heat!) 5 ml of concentrated sulphuric acid.

Silver nitrate solution

Dissolve one big spatula tip of silver nitrate in 10 ml water.