How to make icy patterns

Icy flow­ers on the win­dow even if it's swel­ter­ing out­side? Here’s how!

Safe­ty pre­cau­tions

Only un­der adult su­per­vi­sion.

Equip­ment and reagents

• pho­to frame;
• brush;
• glass;
• 25 mL boil­ing wa­ter;
• 50 g urea.

Step-by-step in­struc­tions

Com­bine 25 mL boil­ing wa­ter and 50 g urea in a glass. Use a brush to ap­ply the re­sult­ing mix­ture to the glass in­sert of a pho­to frame. Let dry.

Process de­scrip­tion

Urea is an or­gan­ic com­pound also known as car­bamide or di­amide of car­bon­ic acid. It is high­ly sol­u­ble in wa­ter: at 20 °С (68 °F), ap­prox­i­mate­ly 108g of urea can dis­solve in 100mL of wa­ter. When heat­ed, urea’s sol­u­bil­i­ty in­creas­es, mean­ing that more of it can dis­solve in a small­er vol­ume of wa­ter. When the so­lu­tion cools, some of the urea pre­cip­i­tates, re­turn­ing the over­sat­u­rat­ed so­lu­tion to a sat­u­rat­ed state. When ap­plied to a sur­face, the wa­ter evap­o­rates and the urea starts to crys­tal­lize. With time, only urea crys­tals are left on the glass in­sert. Urea crys­tals have a nee­dle-like struc­ture and look like frost.

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