Super Powder

Do you want to uncover the mystery of salt?

Ta­ble salt, also known as sodi­um chlo­ride, is a quite enig­mat­ic sub­stance. Imag­ine, the white pow­der you are ef­fort­less­ly sprin­kling on your fries, was of­ten as valu­able as gold in the past cen­turies. For ex­am­ple, Venice be­came a wealthy coun­try be­cause it suc­ceed­ed in ex­ca­vat­ing salt and trad­ing it with oth­er coun­tries. Tax­a­tion of salt was a re­li­able in­come for coun­tries such as Chi­na (2000 B.C), Egypt (323 B.C) and Britain (19th cen­tu­ry). Not to men­tion that be­fore the me­dieval pe­ri­od salt was the most com­mon method to pre­serve food.

To­day we still rely on this es­sen­tial min­er­al. We need it to sur­vive.

Per­haps look­ing at salt’s prop­er­ties and func­tions will help us find out what makes it so spe­cial.

To be­gin with the phys­i­cal prop­er­ties, salt is a crys­talline cu­bic sub­stance with a sharp, salty taste and white or clear sol­id col­or. It be­gins to boil at 1,465 °C and has a mo­lar mass of 58.44 grams per mol and com­pa­ra­bly high melt­ing point of 801 °C.

In chem­istry, sodi­um chlo­ride, with the for­mu­la NaCl, is an ion­ic com­pound made up of equal num­bers of pos­i­tive­ly charged sodi­um ions (Na+) and neg­a­tive­ly charged chlo­ride ions (Cl-). As you know, op­po­sites at­tract, and the two ions bond to­geth­er, cre­at­ing a cu­bic crys­tal lat­tice. The lat­tice is so strong that only po­lar sol­vents (i.e., liq­uids with elec­tri­cal­ly charged mol­e­cules) can break it.

Oc­ca­sion­al­ly, wa­ter is one of those. Wa­ter mol­e­cules are not com­posed of ions yet they are part­ly charged. The hy­dro­gen side is slight­ly pos­i­tive and the oxy­gen side is slight­ly neg­a­tive. Guess what hap­pens when you add some salt to wa­ter. Right, wa­ter gets at­tract­ed to salt! The hy­dro­gen atoms of wa­ter start sur­round­ing neg­a­tive­ly charged chlo­ride ions and the oxy­gen atoms of wa­ter start sur­round­ing pos­i­tive­ly charged sodi­um ions. That new at­trac­tion makes salt dis­solve in wa­ter. By the way, as any oth­er ion­ic com­pound, sodi­um chlo­ride can also con­duct elec­tric­i­ty in its liq­uid state. For the record, near­ly six grams of ta­ble salt could be eas­i­ly dis­solved in 100 grams of wa­ter.

In­ter­est­ing­ly, the sol­u­bil­i­ty makes salt a per­fect life­guard dur­ing a slip­pery win­ter sea­son. Salt can low­er the wa­ter’s freez­ing point (0 °C), mak­ing ice melt. That is how salt pre­vents you from slip­ping on icy roads!

In ad­di­tion, the sol­u­bil­i­ty makes salt a high­ly ef­fec­tive food preser­va­tive as it re­moves wa­ter from the tis­sues of meats and fish, killing the bac­te­ria.

Sure, find­ing salt is easy to­day. Ev­ery gro­cery store has it. And if it doesn’t, you will be kind of sur­prised, right? How­ev­er, did you know that salt makes a long way to ap­pear on your ta­ble?

Let’s take a quick trip to the ocean. Ev­ery time you dive, snorkel or swim in the ocean, you get a gen­er­ous por­tion of salt. But if you can taste salt, why can’t you see the ac­tu­al crys­tals?

In fact, the crys­tals of salt can only be found in shal­low ponds that are ex­posed to the sun and wind. The sun and wind evap­o­rate wa­ter from the sides of coastal rock ponds, leav­ing the salt be­hind. Once a year, when the salt reach­es a cer­tain thick­ness, peo­ple har­vest it from the coastal ponds; then the salt gets rinsed and sift­ed.

The ear­li­est way of salt pro­duc­tion, so­lar evap­o­ra­tion is com­mon in trop­i­cal ar­eas with lit­tle rain­fall and a lot of sun. To date, Pink Lake in West­ern Aus­tralia and the San Fran­cis­co Bay in the Unit­ed States are some of the ma­jor ar­eas where salt is col­lect­ed from shal­low ponds.

Where­as in coun­tries that can­not rely on the sun, peo­ple ob­tain salt through min­ing rocks or boil­ing salt so­lu­tions from brine springs.

Rock salt is the com­mon name for halite, a min­er­al that lives deep be­low the skin of the earth. It might be hard­er to rec­og­nize salt in halite be­cause it can have a slight­ly yel­low, blue, pink or gray col­or. Even the taste of rock salt is not very salty. That is be­cause rock salt con­tains im­pu­ri­ties that lessen the salty taste and bring ad­di­tion­al col­ors to the min­er­al. Hence, con­tam­i­nat­ed by mag­ne­sium and cal­ci­um chlo­ride, rock salt is not so de­sir­able for food fla­vor­ing and preser­va­tion as brine salt. Nev­er­the­less, it works es­pe­cial­ly well for de-ic­ing roads in snowy ar­eas.

One of the largest mines at Wins­ford in Cheshire (UK) pro­duces about a mil­lion tonnes of salt per year. Imag­ine how much salt is hid­den un­der­ground!

Com­par­a­tive­ly, brine springs are high­ly con­cen­trat­ed so­lu­tions of salt be­cause they lack im­pu­ri­ties. Boil­ing down those so­lu­tions gives high-qual­i­ty salt that is com­mon­ly used to fla­vor food and keep it safe to eat.

Be­yond the pop­u­lar do­mes­tic ap­pli­ca­tions, peo­ple use salt in many in­dus­tries in­clud­ing chem­i­cal pro­duc­tion, wa­ter soft­en­ing, medicine, agri­cul­ture, etc. Large amounts of sodi­um chlo­ride go to in­dus­tri­al man­u­fac­tur­ing to make ev­ery­thing from plas­tic, pa­per and glass, to de­ter­gents, soaps and kinds of tooth­paste.

Sig­nif­i­cant­ly, salt is free of calo­ries and nu­tri­ents ex­cept for sodi­um and chlo­ride. So why it is good for us?

Let’s start off with sodi­um. This el­e­ment is vi­tal for main­tain­ing blood pres­sure, reg­u­lat­ing flu­ids in our bod­ies and trans­mit­ting nerve im­puls­es. As for chlo­ride, it helps main­tain the body’s acid-base bal­ance and kill germs that ar­rive with the food we eat.

Un­doubt­ed­ly, both el­e­ments are es­sen­tial for life. As our bod­ies lose salt ev­ery day when we sweat or uri­nate, we need to com­pen­sate for that loss.

Luck­i­ly, in nor­mal life, we need just a lit­tle more than half a tea­spoon of salt per day. In gen­er­al, the foods such as meats, seafood, eggs, milk and veg­gies can eas­i­ly give us that amount. They are nat­u­ral­ly rich in sodi­um com­pared to piz­zas, chips and canned meats that have salt added dur­ing cook­ing.

Not con­sum­ing enough salt can cause some hor­ri­ble symp­toms such as nau­sea, cramps and loss of ap­petite and en­er­gy. In ex­treme cas­es, the de­pri­va­tion of salt can lead to death. There­fore, ath­letes are en­cour­aged to con­sume sodi­um-rich drinks dur­ing in­tense work­outs or marathons.

Re­mem­ber though that too much salt is just as harm­ful as salt de­pri­va­tion. It can in­crease blood pres­sure and lead to heart at­tack, stroke and even heart fail­ure. Lis­ten to your body: feel­ing thirsty, bloat­ed or crav­ing for chips might sig­nal you are eat­ing more salt than you ac­tu­al­ly need.

Sure, it is ok to share a bag of chips with a friend once in a while. Just make sure you do not eat them on dai­ly ba­sis.

As if the ac­tu­al func­tions of salt were not enough, peo­ple have giv­en dif­fer­ent su­per­nat­u­ral mean­ings to that com­pound since an­cient times. For in­stance, An­cient Greeks and Ro­mans of­fered salt to the gods dur­ing the sac­ri­fices. Na­tive Hawai­ians used salt to bless their new ca­noes. In Haiti, the only way to bring zom­bies back to life was to feed them salt…

As you can see, the abil­i­ties of salt are re­al­ly im­pres­sive. The key prop­er­ties make that com­pound in­dis­pens­able in many ar­eas of life and es­sen­tial for over­all well-be­ing. So, be­lieve it or not, there is a set of su­per­pow­ers in your salt shak­er!