Electrolysis of ammonium chloride solution

You have certainly performed the electrolysis of sodium chloride solutions before. Why don’t you investigate the electrolysis behavior of aqueous ammonium chloride solutions? Once again you can learn a lot of chemistry. Electrolysis of ammonium chloride solution Fill an ammonium chloride solution (w = 10%) into a U-tube with a diaphragm. Dip two clean graphite… Continue reading Electrolysis of ammonium chloride solution

Copper tetramine complex

Chemicals Copper (II) sulfate solution (c=0.1 mol l) (Xn), ammonia solution (c=2 mol/l) (Xi), concentrated sulfuric acid (C) How-to a) Add ammonia solution drop by drop to the copper (II) sulfate solution in a test tube until a light blue precipitate forms. Then add more ammonia solution until a clear solution forms. b) Now add… Continue reading Copper tetramine complex

Testing for nitrogen

Equipment 2 beakers (100 ml), 2 watch glasses, spatula, dropper pipettes, Bunsen burner to cover the beaker. Chemicals Ammonia water (C), ammonium chloride (Xi), sodium hydroxide (C), red litmus paper, or universal indicator paper. How-to Put on protective goggles. Do not smell the gases directly! 1 Analysis of liquid ammonia solution A few ml of… Continue reading Testing for nitrogen

Ammonia fountain

Equipment 2-L round bottomed flask, 2-L beaker, 2-hole stopper, Glass tube (2 ft. in length), Ring stand and clamps, medicine dropper, Chemicals Dry NH3 gas or apparatus to produce NH3, Water, Phenolphthalein How-to Fill the 2-L flask with ammonia gas and seal it with a rubber stopper. Ammonia can be generated by gently heating a… Continue reading Ammonia fountain

Ammonium chloride mist

Equipment Beaker (100 ml) or test tube. Chemicals Conc. Ammonia water (C), conc. Hydrochloric acid (C). How-to Put on protective goggles. Keep both substances away from the body. For better contrast, it is recommended to use a dark (black) background. When ready, open both bottles and hold them close to each other. We can also… Continue reading Ammonium chloride mist

Experiments with acetylene

Addition of bromine to ethyne We put bromine water in a cylinder filled with acetylene gas and close it again. We make sure that only a little dilute bromine water is added. Then we shake well. Only a small amount of bromine is added. This is surprising, since a high level of bromine consumption is… Continue reading Experiments with acetylene

Colorful Fire Recipes

The last days of the year are always super colorful, especially when it comes to fireworks. But how do all these different colors work? This is not about short-lived colored flames, which can be created by holding the appropriate salts in a Bunsen burner flame. Examples are copper (II) chloride (or alternatively a mixture of… Continue reading Colorful Fire Recipes

Fluorescein synthesis

Equipment Porcelain bowl or small beaker (50 ml), crucible tongs, Bunsen burner, beaker (400 ml), if available: UV lamp. Chemicals Resorcinol (Xi), phthalic anhydride (Xi), concentrated sulfuric acid (C), dilute sodium hydroxide solution (w = 5%, C), dilute hydrochloric acid (c = 0.1 mol / l, Xi), possibly ethanol (F). How-to A spatula tip each… Continue reading Fluorescein synthesis

Synthesis of phenolphthalein

The name phenolphthalein indicates that the substance is made from phenol and phthalic acid. Equipment Test tube, beaker (400 ml), pipettes, filter Chemicals Phenol (C), phthalic anhydride (Xn), concentrated sulfuric acid (C), sodium hydroxide solution (c=1 mol/l; C), hydrochloric acid (c=1mol/l; Xi). How-to The same amounts of phenol and phthalic anhydride are mixed in a… Continue reading Synthesis of phenolphthalein

Blood orange titration

Instead of an alcoholic solution of phenolphthalein (F), a dispensed solution of blood orange juice is used as an indicator. Blood oranges contain a special plant pigment. This pigment serves as an indicator. Equipment Erlenmeyer flask (250 ml), juicer, burette (50 ml), measuring cylinder (100 ml). Chemicals and materials Lemon (+red cabbage as an indicator),… Continue reading Blood orange titration