Easy Cooking Examples of Chemical Reactions to Use in Class

There are sev­er­al chem­i­cal re­ac­tions you can safe­ly and eas­i­ly per­form at home. The fol­low­ing ex­per­i­ments are gen­er­al­ly easy to find sup­plies for, easy to im­ple­ment, and safe with the ob­ser­vance of ba­sic pre­cau­tions. Which of these will end up on your to-do list?

[Deposit Photos]

1 — "Sug­ar snake"

This demon­stra­tion is like­ly the most spec­tac­u­lar ex­per­i­ment among safe chem­i­cal re­ac­tions. You'll need a fire-re­sis­tant slab, a tablet of sol­id fuel, and two tablets of cal­ci­um glu­conate (most like­ly avail­able at your lo­cal phar­ma­cy). The ex­per­i­ment is sim­ple. Set the sol­id fuel on the tile and ig­nite it, then use tweez­ers to add two tablets of cal­ci­um glu­conate. Ob­serve as the sub­stance twists and morphs into long rib­bons that re­sem­ble snakes. This re­ac­tion has a sim­ple ex­pla­na­tion: as the cal­ci­um glu­conate burns, it re­leas­es car­bon diox­ide, which fills and dras­ti­cal­ly in­creas­es the vol­ume of the burnt sub­stance.

2 — Cop­per(II) hy­drox­ide and glu­cose

To con­duct this ex­per­i­ment, you'll need cop­per(II) sul­fate, an al­ka­li so­lu­tion of sodi­um hy­drox­ide (sold in hard­ware stores), and a glu­cose so­lu­tion (sold in phar­ma­cies). Mix­ing cop­per(II) sul­fate and sodi­um hy­drox­ide will yield a blue pre­cip­i­tate. Grad­u­al­ly adding glu­cose and heat­ing will cause the blue pre­cip­i­tate to dis­ap­pear, and the so­lu­tion will turn first yel­low, then red.

3 — Chem­i­cal lamp

You'll need a trans­par­ent bot­tle, wa­ter, sun­flow­er oil, an as­pirin, and red or blue food col­or­ing. To make the lamp, mix the sun­flow­er oil and wa­ter in the bot­tle. Pour the food col­or­ing into the emul­sion and add the as­pirin. Col­ored flakes will rise to the sur­face of the emul­sion with­out mix­ing with the oil. If you shine a light through the so­lu­tion in the dark, the lamp will glow a mes­mer­iz­ing red or blue.

[Flickr]

4 — Green flame

Be sure to wear gloves and ob­serve spe­cif­ic pre­cau­tions when work­ing with sul­fu­ric and boric acids. Boric acid crys­tals can be pur­chased at your lo­cal phar­ma­cy. This re­ac­tion re­quires boric acid crys­tals, ethyl al­co­hol, porce­lain, a heat-re­sis­tant cup, and sev­er­al drops of sul­fu­ric acid. Start by adding ethyl al­co­hol to a porce­lain cup con­tain­ing boric acid crys­tals. Then add two drops of sul­fu­ric acid and set fire to the so­lu­tion. The flame will turn green due to the com­bus­tion of a com­pound of ethyl al­co­hol and boric acid – so-called tri­ethyl bo­rate. This process can be il­lus­trat­ed with two chem­i­cal re­ac­tions:

3С₂Н₅ОН + Н₃ВО₃ = (С₂Н₅О)₃В + 3Н₂О

2(С₂Н₅О)₃В + 18О₂ = В₂О₃ + 12СО₂ + 15Н₂О

Warn­ing! Do not han­dle sodi­um tetrab­o­rate if preg­nant!

5 — Mak­ing an iron nail "cop­per"

For this ex­per­i­ment, you'll need a cop­per wire, an iron nail, acetic acid (vine­gar), ta­ble salt, and bak­ing soda. First, mix the vine­gar with the salt and im­merse an iron nail in the so­lu­tion. Then, clean the sur­face of the cop­per wire with bak­ing soda and place it in the so­lu­tion. Wait for half an hour and re­trieve the iron nail, which should now be cov­ered in cop­per. This oc­curs via two re­ac­tions: the re­ac­tion of cop­per with acetic acid in the pres­ence of at­mo­spher­ic oxy­gen, and the sub­sti­tu­tion of the ob­tained cop­per ac­etate with iron ac­etate.

6 — Non-flammable mon­ey

Ap­ply some potas­si­um alum so­lu­tion to a ban­knote. Place the treat­ed bill in a pa­per en­ve­lope, hold the en­ve­lope with tweez­ers, and set fire to it. The en­ve­lope will burn, but the ban­knote will re­main un­scathed. The mon­ey doesn't burn due to the alum, which it­self does not burn, and doesn't al­low the bill to burn.

[Deposit Photos]

7 — Non-flammable mon­ey (2)

To con­duct this ex­per­i­ment, you'll need to mix half a glass of 96% ethyl al­co­hol and half a glass of wa­ter, then dis­solve a pinch of salt in the re­sult­ing so­lu­tion. Use tweez­ers to dip a ban­knote in the so­lu­tion for a few sec­onds, then take it out and and set fire to it with a lighter. The ethyl al­co­hol coat­ing the bill will burn away, while the sod­den ban­knote will re­main un­harmed. Once it dries out, you can use it just as you nor­mal­ly would!

8 — Starch and io­dine

To con­duct this ex­per­i­ment, you'll need a heat-re­sis­tant flask, 20 g of starch, and 5 drops of io­dine so­lu­tion. Mix the starch with wa­ter, then add the io­dine so­lu­tion. At room tem­per­a­ture, the so­lu­tion turns dark blue. If you heat the ob­tained so­lu­tion on an elec­tric stove, it will turn col­or­less once again. This re­ac­tion can serve to prove that starch can form a com­pound with an io­dine so­lu­tion. As the so­lu­tion of io­dine and starch is un­sta­ble, the starch re­forms when heat is ap­plied, and the free io­dine evap­o­rates. Look here for more in­ter­est­ing ex­per­i­ments with starch.

9 — Potas­si­um per­man­ganate and hy­dro­gen per­ox­ide

First, pul­ver­ize a tablet of UHP (hy­dro­gen per­ox­ide - urea) and trans­fer the pow­der to a glass jar. Add liq­uid soap and wa­ter. Next, pre­pare an aque­ous so­lu­tion of potas­si­um per­man­ganate. Pour the potas­si­um per­man­ganate so­lu­tion into the glass jar with soap and hy­dro­gen per­ox­ide. Ob­serve the vi­o­lent ox­i­da­tion-re­duc­tion re­ac­tion and the for­ma­tion of pink foam. This re­ac­tion re­leas­es oxy­gen, which fills the liq­uid soap with gas bub­bles and helps cre­ate foam. The chem­i­cal re­ac­tion takes place ac­cord­ing to the equa­tion:

4KM­nO₄ + 4H₂O₂ = 4M­nO₂ + 5O₂↑+ 2H₂O + 4KOH

We should note that you ab­so­lute­ly should not touch the al­ka­line so­lu­tion ob­tained in the re­ac­tion.

10 — Bak­ing soda and acetic acid

To ini­ti­ate the re­ac­tion, pour 20 g of bak­ing soda into a glass jar and add 50 mL of acetic acid. The bak­ing soda will start to foam, re­leas­ing car­bon diox­ide. The re­ac­tion takes place ac­cord­ing to the equa­tion:

NaH­CO₃ + CH₃­COOH = CH₃­COONa + H₂О + CO₂↑

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Source: https://melscience.com/US-en/articles/top-10-safe-chemical-reactions/

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