What is sodium bicarbonate?

More about baking soda

[Deposit Photos]

Sodi­um bi­car­bon­ate can be found in al­most ev­ery kitchen, as this white pow­der known as bak­ing soda is used in prac­ti­cal­ly all spheres of life; in cos­met­ics, in cook­ing and in house­hold chores.

Let’s find out more about bak­ing soda

Sodi­um bi­car­bon­ate has the for­mu­la NaH­CO₃, and it has the fol­low­ing prop­er­ties:

  • it looks like a white pow­der, and eas­i­ly dis­solves in warm wa­ter;
  • bak­ing soda is safe to use. It does not burn, and can­not be used as an ex­plo­sive;
  • it is salty and bit­ter to the taste, and some­what ir­ri­tat­ing to the tongue and mu­cous mem­branes;
  • neu­tral­izes acids, so soda is used in first aid to treat ex­ter­nal burns.
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How bak­ing soda is pro­duced

In in­dus­tri­al pro­duc­tion, NaH­CO₃ is ob­tained by a spe­cial method which is called am­mo­ni­ac-chlo­ride: in a high­ly con­cen­trat­ed so­lu­tion of sodi­um chlo­ride en­riched with am­mo­nia, car­bon diox­ide is re­leased, and so bak­ing soda is ob­tained.

The equa­tion of the re­ac­tion can be writ­ten as fol­lows:

NH₃ + CO₂ + H₂O → NH₄H­CO₃;

NH₄H­CO₃ + NaCl → NaH­CO₃↓ + NH₄­Cl.

As soda dis­solves poor­ly in cold wa­ter, it is eas­i­ly sep­a­rat­ed by fil­tra­tion. In­ci­den­tal­ly, from the am­mo­ni­um chlo­ride ob­tained as a re­sult of the re­ac­tion, am­mo­nia can be chem­i­cal­ly pro­duced once more.

Sodi­um bi­car­bon­ate is used in many spheres, for ex­am­ple:

  • medicine, in treat­ing acid burns, rins­ing the throat, mouth and nasal phar­ynx;
  • in the food in­dus­try (of­fi­cial name of the food ad­di­tive NaH­CO₃ – E500);
  • in mak­ing pas­tries and bread;
  • in the beau­ty in­dus­try: soda is used for wash­ing hair and whiten­ing teeth;
  • this white pow­der can al­ways be used in fire-fight­ing.
A small, disposable sodium bicarbonate dry chemical unit intended for home kitchen use [Wikimedia]

In­ter­est­ing fact: if you heat sodi­um bi­car­bon­ate to a tem­per­a­ture of 60 °C, the sub­stance breaks down into sodi­um car­bon­ate Na₂­CO₃, wa­ter and car­bon diox­ide.

Re­ac­tion of soda with acids

Bak­ing soda re­acts with acids in a spe­cial way: first car­bon­ic acid forms (which then breaks down into H₂О and CO₂) and salt.

Re­ac­tion equa­tion:

NaH­CO₃ + HCl → NaCl + H₂­CO₃

H₂­CO₃ → H₂O + CO₂↑

You can keep see this re­ac­tion us­ing or­di­nary vine­gar., If you add acetic acid to a tea­spoon of bak­ing soda, it will im­me­di­ate­ly start to hiss: bub­bles will form and break on the sur­face of the salt. This method is used by cooks to make dough fluffi­er.

The re­ac­tion of sodi­um bi­car­bon­ate and vine­gar:

NaH­CO₃ + CH₃­COOH → CH₃­COONa + H₂O + CO₂↑

As a re­sult of the in­ter­ac­tion of vine­gar and sodi­um bi­car­bon­ate, a sub­stance is forms called sodi­um ac­etate, CH₃­COONa, which is wide­ly used in in­dus­tri­al pro­duc­tion.

Skeletal formula of sodium acetate [Wikimedia]

A sim­ple ex­per­i­ment with soda: lots of foam

Kids will love this ex­per­i­ment, as it looks spec­tac­u­lar.

Warn­ing! Vine­gar is an acid which dam­ages the res­pi­ra­to­ry tracts and may leave burns on the skin (es­pe­cial­ly if it is high­ly con­cen­trat­ed). Be care­ful.

To make the foam you will need:

  • wa­ter;
  • liq­uid soap or dish-wash­ing liq­uid;
  • sodi­um bi­car­bon­ate (bak­ing soda);
  • gloves;
  • stir­ring rod;
  • bot­tle (you can use a 500 ml con­tain­er for the ex­per­i­ment);
  • acetic acid;
  • tray.

In a sep­a­rate con­tain­er mix the dish­wash­ing liq­uid and wa­ter, as in vine­gar the soap ef­fect will not work, and add four tea­spoons of soda. Mix well and pour the so­lu­tion into the bot­tle.

Place the bot­tle on the tray to keep the ta­ble clean, and quick­ly add 100 ml of vine­gar, and so you will see an im­pres­sive ef­fect, the for­ma­tion of a large amount of foam. This ex­per­i­ment is ex­plained by the fact that car­bon diox­ide is ac­tive­ly formed from vine­gar and soda, which “mix­es” the wa­ter and soap to a foam. Click here for more ex­per­i­ments with bak­ing soda.

An­oth­er ex­per­i­ment: blow up a bal­loon us­ing soda

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You will need:

  • soda;
  • vine­gar;
  • bot­tle;
  • bal­loon.

This method is very suit­able if you need to blow up a lot of bal­loons for a par­ty (if you do not have a spe­cial de­vice).

Sim­ply add soda, and then vine­gar (a lot of car­bon diox­ide should be re­leased, so use around one third of a bot­tle of vine­gar and sev­er­al ta­ble­spoons of soda). Put the bal­loon over the neck of the bot­tle, and you will see the bal­loon in­flate quick­ly, from the gas that forms as a re­sult of the re­ac­tion. These bal­loons won’t float.