“Sugar crystals” experiment

Kids will love this ex­per­i­ment! It’s the most de­li­cious ex­per­i­ment for grow­ing crys­tals.

Safe­ty pre­cau­tions

Ob­serve safe­ty rules when work­ing with heat­ing de­vices.

Warn­ing! Only un­der adults su­per­vi­sion.

Reagents and equip­ment:

• saucepan;
• sug­ar;
• wa­ter;
• bam­boo sticks;
• glass;
• food col­or­ing (any kind);
• foil;
• pa­per clamp;
• fry­ing pan.

Step-by-step in­struc­tions

Pre­pare the seed for crys­tals: add sug­ar and wa­ter to a fry­ing pan in the ra­tio of 10:1 and heat un­til the sug­ar dis­solves com­plete­ly. Pour the thick syrup into a bowl and dip the bam­boo sticks in it, then sprin­kle plen­ty of sug­ar on them, so it sticks. Leave to dry for a few hours.

Pre­pare the so­lu­tion to grow the crys­tals: add sug­ar and wa­ter to a saucepan in the ra­tio of 3:1 and heat slow­ly un­til the sug­ar dis­solves com­plete­ly. Leave the syrup on the hot plate to cool for 15-20 min­utes. Pour the cooled syrup into glass­es and add food col­or­ing.

Im­merse the sticks ver­ti­cal­ly in the cen­ter of each glass of syrup. They must not touch the bot­tom of the glass, or the walls! Cov­er with foil and leave in a dark place. Two weeks lat­er beau­ti­ful sug­ar crys­tals will grow on the sticks.

Pro­cess­es de­scrip­tion

At room tem­per­a­ture (25 °С, 77 °F), the sol­u­bil­i­ty of sug­ar in wa­ter is around 200 g/100 g of wa­ter. When heat­ed, the sol­u­bil­i­ty of sug­ar in­creas­es and more of it dis­solves in wa­ter. When cooled, the so­lu­tion be­comes over­sat­u­rat­ed, i.e. more of the sub­stance is dis­solved at the giv­en tem­per­a­ture. As a re­sult, the “sur­plus sub­stance” pre­cip­i­tates in the form of crys­tals, and the so­lu­tion once more be­comes sat­u­rat­ed. To grow large sug­ar crys­tals, a seed for crys­tal­liza­tion in the form of a stick is re­quired. Two weeks lat­er the sug­ar grains turn into a can­dy.