What is Salt: Definition and 273 Discussions

Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantities in seawater. The open ocean has about 35 grams (1.2 oz) of solids per liter of sea water, a salinity of 3.5%.
Salt is essential for life in general, and saltiness is one of the basic human tastes. Salt is one of the oldest and most ubiquitous food seasonings, and salting is an important method of food preservation.
Some of the earliest evidence of salt processing dates to around 6,000 BC, when people living in the area of present-day Romania boiled spring water to extract salts; a salt-works in China dates to approximately the same period. Salt was also prized by the ancient Hebrews, the Greeks, the Romans, the Byzantines, the Hittites, Egyptians, and the Indians. Salt became an important article of trade and was transported by boat across the Mediterranean Sea, along specially built salt roads, and across the Sahara on camel caravans. The scarcity and universal need for salt have led nations to go to war over it and use it to raise tax revenues. Salt is used in religious ceremonies and has other cultural and traditional significance.
Salt is processed from salt mines, and by the evaporation of seawater (sea salt) and mineral-rich spring water in shallow pools. Its major industrial products are caustic soda and chlorine; salt is used in many industrial processes including the manufacture of polyvinyl chloride, plastics, paper pulp and many other products. Of the annual global production of around two hundred million tonnes of salt, about 6% is used for human consumption. Other uses include water conditioning processes, de-icing highways, and agricultural use. Edible salt is sold in forms such as sea salt and table salt which usually contains an anti-caking agent and may be iodised to prevent iodine deficiency. As well as its use in cooking and at the table, salt is present in many processed foods.
Sodium is an essential nutrient for human health via its role as an electrolyte and osmotic solute. Excessive salt consumption may increase the risk of cardiovascular diseases, such as hypertension, in children and adults. Such health effects of salt have long been studied. Accordingly, numerous world health associations and experts in developed countries recommend reducing consumption of popular salty foods. The World Health Organization recommends that adults consume less than 2,000 mg of sodium, equivalent to 5 grams of salt per day.

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  1. N

    Differential Equations: Salt Concentration and logs

    Homework Statement A tank initially contains 180 gallons of water in which 8grams of salt are dissolved. Water containing 9 grams of salt per gallon enters the tank at the rate of 3 gallons per minute, and the well mixed solution leaves the tank at the rate of 1 gallon per minute. The...
  2. B

    Calculating [OH-] from an acid and salt.

    Homework Statement Calculate the [OH-] concentration in a 0.5 M solution of potassium fluoride (KF). Ka for HF is 7.2 × 10−4.The Attempt at a Solution I know that KF → K+ + F-, therefore having a 1:1 ratio, [F-] = 0.5M ,but from here I am unsure what to do with the F- concentration. I know that...
  3. E

    Freezing Salt Water Experiment

    I'm in a bit of a time crunch for science fair, and there are still a few questions about my experiment that are unanswered. What I'm dong is trying to accelerate the freezing of salt water by adding electrodes to the bottom of my container (attached to a battery). If the ions of the salt are...
  4. P

    I'm making ham stew and I sprinkle salt on top of the liquid. Will is disperse?

    What are the factors affecting dispersion of salt in a mixture? Obviously stirring will guarantee effective mixing, but I'm wondering how much I could expect the salt to disperse throughout the stew if I were to not touch it. The stew is near/at boiling (100 C), but it is not vigorously...
  5. M

    Why is the salt solubility curve flat?

    I know most salts' have increased solubility in 100g of water with an increase in temperature, a few have an inverse relationship, but why does NaCl flatline regardless of temperature? Like is there a mechanism that explains this phenomenon? Thanks in advance.
  6. B

    [Chemistry] Salt in an acetic acid solution with copper

    Homework Statement Basically I'm doing a lab report where we place copper pennies in a solution of salt and vinegar. This should strip the copper oxide off the outside of the pennies, leaving the copper underneath shiny and looking "new". The problem is why we add the salt. Homework...
  7. N

    Is the solubility of a salt affected by how much salt you add to a solution?

    Hey. Will a saturated solution of a salt at a constant temperature and pressure have a constant amount of dissolved salt even as you add more salt? Let us pretend that acid-base or metal-complex reactions don't happen.
  8. J

    An electrolysis reaction: Silver electrode and cathode, Rochelle Salt solution

    Hi I'm new to the forum, so first I want to say hello to everyone. I have been interested in Colloidal Silver lately, and I have produced it with electrolysis in distilled water with NaCl as an electrolyte. I have used a Silver electrode and cathode for both of these experiments. I...
  9. C

    Medical Why is potassium important in controlling blood pressure?

    I regularly hear people say that eating salt is bad for the health and the heart etc. Why is this? I know that the bodies electrolites such as Na+, K+, Ca2+, Cl- etc. need to be balanced so ingesting too much NaCl will cause electrolyte imbalance, is that what people are referring to when they...
  10. L

    How Electrodes in salt solution can increase the electric potential

    Hello, I'm not sure if this is the right place for this question, but I am trying to understand how placing electrodes in the brain elicits action potentials. In a neuron (brain cell), there exists a solution of sodium and potassium ions (among other things). When the brain wants to...
  11. L

    Medical How Electrodes in salt solution can increase the electric potential

    Hello, I'm not sure if this is the right place for this question, but I am trying to understand how placing electrodes in the brain elicits action potentials. In a neuron (brain cell), there exists a solution of sodium and potassium ions (among other things). When the brain wants to produce an...
  12. C

    Fiberglass degradation by salt water

    People always wash their fiberglass boats, the part above water obviously. I was thinking if there is really a need for it? What is suitable to degradation, the plastic matrix, or the fibers of glass? And how does salt water promotes that degradation? Thank you Regards
  13. F

    Where can I find a salt bath that reaches 600°C?

    I am looking for a standalone salt bath that can reach temperatures of 600°C. Maybe 1 foot tall and 1/2 foot wide at the base. Does anyone know where I can find one online?
  14. C

    Salt Battery: Choosing anode/cathode

    I want to build a salt battery, and I've seen them use Zinc and Copper. But what if I replaced Zinc with Tungsten, since it has an ion charge of 6+. Would that increase the amount of ions, released into the water, and increase the power output? Do you have any suggestions for more potent...
  15. A

    A2 Physics Experiment: Electrical Conductance Through Salt Solution

    After summer I have to do my physics A2 experiment coursework. I really like working with electricity and looking at what happens at an atomic level, but I fear that what I want too do is more chemistry than physics. I had the idea of look at electrical conductance through a salt solution...
  16. fluidistic

    Medical Can you get a healthy diet without adding salt to food?

    Considering one is in good shape and exercise a few times a week, can he have a healthy diet without adding sea/table salt to his food? I think there's salt in many products that one eats so I wonder if adding salt to food is necessary to have a good diet and therefore, health.
  17. N

    Why did the salt solution evaporate and leave deposits on the beaker?

    I was messing around with a saturated solution of table salt, when I forgot about it and left it in a fume hood over night. When I came in the next morning the solution had evaporated away, but what surprised me was that there were salt deposits left on the beaker above the initial height of...
  18. J

    Flouride salt safety issues? (high temperature)

    Hello, I am working a on a project to improve the thermal properties (heat capacity, thermal conductivity) of heat transfer fluids used in concentrated solar power (CSP). First a suitable base fluid is required, the higher the working temperature the better for thermal efficiency. Most of the...
  19. S

    Cracking of hydrocarbons and boiling point of salt water

    Can alkenes be cracked or only alkanes can be cracked? Then what would the products be? Like for alkanes a alkenes must always be formed but what about for alkenes cracking? Also, when we boil salt water its temperature is 101.4 degrees. But when performing fractional or simple distillation...
  20. Artlav

    Is it Possible to Make an MWIR Lens from Melted Table Salt?

    I was thinking of making an MWIR lens from table salt, which is quite transparent for it. That needs a big, monolithic cylinder of salt - 3x1 cm. Now, growing it the classic-oversaturated-solution way would take forever, if feasible at all. And i want to try to just melt some salt and cast...
  21. P

    Why Does Salt Spray Out of Water in a Shaker Experiment?

    I have done a small experiment I dissolved salt into normal tap water using a shaker... I put as much salt as the specific quantity of water could dissolve no more no less... I left the cup there for a while and after some time I saw that salt was spreading ABOVE the water level and OUTSIDE of...
  22. N

    Can Adding Water to Molten Salt Increase the Boiling Point of Salt or Water?

    If adding impurities, such as salt, to water will increase the boiling point of water, what if it's the other way around? Will adding water to molten salt increase the boiling point of salt (sodium chloride) or the water? Or water is not considered an impurities to molten salt?
  23. R

    What is the relationship between salinity and the speed of sound in water?

    I've preformed an experiment about the speed of sound waves in water and I found that sound traveled faster in hot water than cold water (distilled water), but it traveled still faster in salt water. So, how can I explain why the speed of sound increases with salinity? We have the equation: c=...
  24. P

    Deposition of salt from evaporated water

    When a small volume, say 5ml, of saturated solution of NaCl is left on a flat surface and evaporates, why does the salt always become concentrated on the outer edge of the base where the solution was? Why doesn't it form a uniform distribution of salt throughout the entire area which the...
  25. J

    How were cations divided into groups for salt analysis?

    How does salt analysis work? How did they divide cations into these 6 groups? I'm confused over things like:- In a group we precipitate metals through their sulphides - but only few of the metals precipitate - why only specific emtals precipitate. Then in another group we precipitate metals as...
  26. T

    Tilting a Salt Shaker - How Does it Not Tip Over?

    So I go into this restaurant, and I got bored. So, I tilt a salt shaker on a sturdy table and let it go... It doesn't tip over... How do you think this occurs?
  27. C

    Salt absorbtion from the ocean

    I have checked with doctors and even some molecular biologist and can't get a solid answer. I like to wade fish in the ocean and I have Menieres disease. I have to really watch salt in my body. If I fish waist deep in the ocean for 5 or 6 hours a day will the skin allow salt to enter the...
  28. B

    How Does Salt Preservation Work in Meat?

    I was reading this post regarding meat preservation. http://answers.yahoo.com/question/index?qid=20061022184303AALaiDt Basically, salt draws out the water from meat which keeps insects away since insect are attracted to water. There's one point that is glossed over: how does salt...
  29. J

    What Is the Role of Ethanol in Precipitating Salts?

    Homework Statement what is the purpose of adding ethanol in step 5 in the following description? http://www.creative-chemistry.org.uk...s/N-ch5-08.pdf Homework Equations The Attempt at a Solution Does adding ethanol make the liquid phase (which is now a homogenous mixture) less...
  30. T

    Salt water and tap water conducting electricity - help appreciated

    Salt water and tap water conducting electricity - help appreciated :) Hello, Thanks in advance for helping me with my question! I'm so excited to find this physics forum of such talented people. My question is, I know that salt water conducts electricity more than tap water due to the ions...
  31. E

    If an Atom was the size of a grain of salt

    What object would represent the size of a grain of salt at this scale? Would it be bigger than Earth?
  32. A

    Spectrophotometry of chromium salt

    Homework Statement Why is 575 nm wavelength used in spectrophotometry of Potassium dioxalatodiaquochromate (III) dihydrate? Homework Equations none The Attempt at a Solution Cannot find discrete reasoning!
  33. M

    Salt water steam pressure vs fresh water steam pressure

    Homework Statement My son picked a science experiment for his 5th grade project. It was supposed to be on evaporation. Basically a steam powered boat with candles heating up a cigar tube with a hole for the steam to escape and push the boat. However he got ambitious and changed the...
  34. S

    Concentration of salt in the tank

    Help... ? A 200 liter tank initially contains 100 liters of water with a salt concentration of 0.1 grams per liter. Water with a salt concentration of 0.5 grams per liter flows into the tank at a rate of 20 liters per minute. Assume that the fluid is mixed instantaneously and that this...
  35. S

    Solving a Differential Equation: Salt Concentration in a Tank

    can you help me ?? A 200 liter tank initially contains 100 liters of water with a salt concentration of 0.1 grams per liter. Water with a salt concentration of 0.5 grams per liter flows into the tank at a rate of 20 liters per minute. Assume that the fluid is mixed instantaneously and that...
  36. S

    Solving Differential Equations for Tank of Water and Salt

    can you help me ?? A 200 liter tank initially contains 100 liters of water with a salt concentration of 0.1 grams per liter. Water with a salt concentration of 0.5 grams per liter flows into the tank at a rate of 20 liters per minute. Assume that the fluid is mixed instantaneously and that...
  37. 3

    Salt Bridge & Voltaic Cells Experiment

    I did an experiment testing the thickness of a salt bridge (made of filter paper soaked in potassium nitrate) on the voltage produced from Zn and Cu half cells. This is similar to a thread someone made back in 2007. But I have no idea how to explain my findings or whether the thickness...
  38. Saitama

    Identify if the given salt is acidic or not

    I have been coming across some questions which asks to identify whether the given salt is acidic, basic or neutral. I solve them like this:- For example the salt is NaCl, the answer is neutral as NaOH and HCl are strong base and strong acid respectively. But for problems like KF:- I was...
  39. C

    Method to remove salt from water (Not distillation or RO)

    Hello all. I'm tutoring a high school student and am having trouble with a seemingly simple science project that was assigned: How to remove table salt from water. Having graduated as a Chemical Engineer, I said distillation! But the problem statement says you can't be that boring. Then I said...
  40. D

    Deriving Amine Salt: Making Butylamine Hydrochloride Derivative

    Homework Statement I have to make a solid derivative of an unknown compound. All the data I have collected points to the unknown being butylamine hydrochloride. My textbook has suggestions for making derivatives of amines, but nothing for amine salts. Homework Equations The Attempt at a...
  41. L

    Salt Shaker on a Lazy Susan, magnitude of force

    Mischievous Joey likes to play with his family's lazy susan (this drives Mom crazy because it is an antique). He puts the salt shaker near the edge and tries to spin the tray at a speed so that the shaker just barely goes around without slipping off. Joey finds that the shaker just barely stays...
  42. D

    Rusting of Nails in Salt Solutions

    Three tests were conducted where a nail was placed in water, 10%salt saturated, 20% salt saturated, 30% salt saturated etc to 100% a Nail + Cu placed in water (same solutions above^) and A Nail + zinc in water.. (same solutions) All left over the same amount of days The results are...
  43. tony873004

    Why Can't Salt Be Separated from Water Using a Centrifuge or by Letting It Sit?

    Why can’t I separate salt from water with a centrifuge, or simply by letting it sit for some time? Salt water is a homogeneous mixture, not a compound. So the salt and the water are not chemically bonded. Why don’t the denser NaCl molecules sink to the bottom of the H20 molecules?
  44. A

    Rechargable galvanic cell?[remove the salt bridge}

    Rechargable galvanic cell??[remove the salt bridge} In a galvanic cell,a salt bridge is used to maintain potential difference between the two half-cells.Now,once the charge accumulation is maximum,then even the salt bridge cannot maintain potential difference.At this point,what if one removes...
  45. G

    How does a salt bridge prevent charge buildup in a galvanic cell?

    As electrons leave one half of a galvanic cell and flow to the other, a difference in charge is established. If no salt bridge were used, this charge difference would prevent further flow of electrons. Why would the charge difference prevent further flow of electrons ??
  46. sankalpmittal

    How can we know that which salt is soluble or which is not ?

    There is one topic in my chemistry book which is driving me nuts . There is given a solubility chart showing that all Nitrates of metals are soluble without exception . All chlorides are soluble except AgCl and PbCl2I am wondering how do we know which is soluble or which is not (or checking a...
  47. I

    Salt Water Swimming Pool Question.

    How could sodium chloride produce chlorine (neutral atoms rather than ions) in a swimming pool? I have always understood that chlorine takes an electron from sodium, because it's nucleus can pull more strongly on it. So, if the two were broken apart, wouldn't the chlorine keep the electron...
  48. A

    What is the exact definition of a 'salt'?

    What is the exact definition of a 'salt'? This question is bugging me from a long time. Thanks!
  49. S

    If you saturated the air with salt, it becomes dielectric?

    say you vaporized salt and threw it in the air. Would that be enough to turn that volume of air dielectric or would the minute pockets of fresh air in among the salt molecules still block low-med voltage
  50. P

    Dissolving an Unknown Acid Salt - Weak Acids?

    i'm trying to dissolve an unknown acid salt and it is not soluble in water at stp. it does dissolve, however, when it undergoes heat and some stirring. is this property representative of most weak acids, that they are not easily miscible in water?
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