Properties of liquid nitrogen. Laboratory experiments with liquid nitrogen

It is one of the ag­gre­gate states of ni­tro­gen. Spe­cial prop­er­ties of the sub­stance are:

• has no col­or or taste;
• com­par­a­tive in­ert­ness (at high tem­per­a­tures bonds with lithi­um, mag­ne­sium, oxy­gen, hy­dro­gen);
• does not cause cor­ro­sion;
• not flammable;
• not poi­sonous;
• boil­ing point = -196 °С.

Ap­pli­ca­tion of liq­uid ni­tro­gen (LN):

In in­dus­try — for cool­ing sys­tems, cre­at­ing high pres­sure in plas­tic bot­tles when bot­tling oils and non-car­bon­at­ed bev­er­ages, and ob­tain­ing am­mo­nia.

In cos­met­ics — cryother­a­py (mas­sage, re­mov­ing pa­pil­lo­ma).

In medicine — for con­duct­ing sur­gi­cal op­er­a­tions.

In cook­ing — for pre­par­ing ice cream and sor­bet.

Nec­es­sary safe­ty mea­sures in work­ing with LN

• The liq­uid must be stored in spe­cial de­wars.

• Don’t seal the neck of the con­tain­er tight­ly – you can risk dam­ag­ing the con­tain­er and caus­ing an ex­plo­sion.

• Keep track of the ni­tro­gen lev­el in the cylin­der – with a small residue of liq­uid, im­pu­ri­ties con­dense.

• When re­fill­ing or re­mov­ing ma­te­ri­al, don’t look into the con­tain­er – this can dam­age the mu­cous mem­branes.

• Pro­tect ex­posed ar­eas of skin from cryo­gen va­por (long shirt sleeves, mask, glass­es).

Lab­o­ra­to­ry work with liq­uid ni­tro­gen

Ex­per­i­ment №1“Ice flow­er”

The most pop­u­lar ex­per­i­ment. You’ll need a de­war con­tain­ing liq­uid ni­tro­gen and a rose (or any oth­er flow­er, as long as it has a long stem).

Click here to see top 10 ex­per­i­ments with liq­uid ni­tro­gen.

Im­merse the flow­er in the con­tain­er for 15-20 sec­onds. As a re­sult you’ll get a crys­tal-like rose, which will break from a strong blow. This method is used by cooks nowa­days to pre­pare sal­ads.

Ex­per­i­ment №2 “Liq­uid air”

Trans­par­ent bal­loon and LN.

Pro­ce­dure:

1. in­flate the bal­loon.
2. im­merse it in LN.

Re­sult: the im­pact of liq­uid ni­tro­gen, the air bal­loon re­duces in vol­ume, and the air con­dens­es into liq­uid.

Ex­per­i­ment №3 “Big bal­loon”

If you fill a bal­loon with 1 liter of LN, you can ob­serve the bal­loon ex­pand by 70 times. How­ev­er, you must be care­ful, as un­der the im­pact of liq­uid ni­tro­gen the walls of the bal­loon be­come very frag­ile, which can cause an ex­plo­sion. For a more spec­tac­u­lar ex­per­i­ment you can use a plas­tic bot­tle filled with LN, and place it in a bar­rel of wa­ter.

Ex­per­i­ment “Ice cream”

In­gre­di­ents:

• 1 glass of luke­warm milk;
• 50 gr. of cream;
• 3 egg yolks;
• 100 gr. of sug­ar.

Prepa­ra­tion:

1. beat the egg yolks with sug­ar;
2. add milk and cream to the mix­ture;
3. thor­ough­ly mix, and pour in liq­uid ni­tro­gen.

The ice cream can be eat­en im­me­di­ate­ly.

Ex­per­i­ment №5 “Fog”

If you add liq­uid ni­tro­gen to boil­ing wa­ter, in­tense boil­ing will take place, cre­at­ing the ef­fect of white fog.