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.
20 ml Hydrochloric acid 30-33 % into 75 ml water.
10 ml nitric acid 65 % into 60 ml water.
25 ml sulfuric acid 96 % carefully into 398 ml water. Not vice versa!
10 ml Ammonia solution 25 % into 55 ml water.
15 g Sodium hydroxide (biscuits or beads are preferable) into 185 ml water.
15 g Sodium hydroxide (biscuits or beads are preferable) into 60 ml water. Not vice versa, strong heating up!
33 g Sodium hydroxide (biscuits or beads are preferable) into 77 ml water. Not vice versa, strong heating up!
2 g Barium hydroxide (octahydrate) into 50 ml water in a closed botte and shake. Filter out the deposit and store airtight.
See Demonstration of bromine
According to Prof. Blume (German)
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.
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.
Dissolve 2 g potassium iodide in 4 ml water, mix with 1 g Iod, after disolving fill with water to 300 ml.
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.
Dissolve 1 g potassium mangante in 100 ml 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.
Dissolve 1 g sodium nitrite in 25 ml water.
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.
Dissolve one big spatula tip of silver nitrate in 10 ml water.