Which symbols represent the ions in a glass of water

Small green squares enter the cylinder and gradually replace the small red circles attached to the grey spheres. The small red circles travel down and out of the cylinder. The stationary and mobile phases are chosen to selectively retain ionic species. The ionic strength of a solution is a function accounting for the concentration of all the different ions. By changing the ionic strength of the mobile phase, the ions in Figure 7 are eluted, or extracted into the mobile phase here water , from the stationary phase.

The ions bound by the stationary phase are eluted in order of the strength of binding, the most weakly bound ions being eluted first. The binding strength of the ions with the stationary phase depends on the differences in charge and charge density of the various ions present. Why do you think the ion-exchange resin is regenerated by eluting with a concentrated sodium chloride solution? See Figure 7. With a high concentration of chloride ions the nitrate ions are exchanged and the initial chloride form of the ion-exchange resin is regenerated:.

Inorganic arsenic is naturally present at high levels in the groundwater of a number of countries, including Bangladesh, China, India, Mexico, and the USA. Phosphorus displays similar chemistry as it is above arsenic in Group 15 and is indeed replaced by arsenic in organs and tissues within the body. For example, phosphorus can be substituted by arsenic in adenosine triphosphate ATP which plays a fundamental role in metabolism.

In natural waters one of the main sources of arsenic oxoanions is believed to be the weathering of pyrite, FeS 2 , minerals which contain a trace of arsenic. Remarkably, this iron III hydroxide then has a capacity to exchange its surface hydroxide anions and so is able to adsorb arsenite and arsenate anions from natural water effectively restricting their mobility in the environment.

However, this adsorption on iron III hydroxide is pH-dependent, and so the arsenate ions can be re-mobilised into the environment by a pH change. So phosphate can be similarly absorbed. To remove arsenite and arsenate anions from water one method is to add particles of iron III hydroxide and allow time for the anion exchange to take place.

However, where the water is pumped directly from a well for use, a better solution is to use a synthetic ion-exchange medium or resin as in Figure 8 and similar to what you previously saw for the removal of nitrate from water. Ion-exchange is almost instantaneous, a big advantage over adsorption processes using iron III hydroxide.

After a few months the medium becomes saturated with arsenate ions and so is regenerated by eluting with a sodium chloride solution. This process presupposes a safe means of disposing of the eluted arsenate containing solution. In practice, it has been observed that oxidation is beneficial before the removal of arsenic oxoanions.

What is the chemistry behind this observation? Arsenate will be more fully deprotonated at neutral pH because arsenic acid is a stronger than arsenous acid. Consequently there will be a higher negative charge and greater electrostatic attraction to the cationic resin. Phosphorus compounds are hugely important in nature, for example deoxyribonucleic acid DNA is a polymer of alternating phosphate and deoxyribose groups. In this section you will see that phosphorus forms firstly relatively simple anions such as phosphate, PO 4 Then you will explore the chemistry of polyphosphates such as adenosine triphosphate ATP that was mentioned in Section 2.

Most detergents or surfactants, comprise long molecules with hydrophobic water-repelling and hydrophilic water-attracting parts as indicated in the example in Structure 6. The basic action is for the organic hydrophobic section to bury itself in the dirt, and the hydrophilic section then allows the insoluble dirt to 'dissolve' in water.

Detergents are used in combination with so-called builders, which soften hard water. Hard water contains significant concentrations of calcium and magnesium salts, which replace the sodium ions in the detergent molecule. The dipositive metal ions cause the long detergent molecules to clump together and precipitate out as a scum.

Sodium tripolyphosphate Structure 7 see also Section 3. Due to environmental concerns over such polyphosphates acting as nutrients for algae leading to eutrophication , detergent manufacturers have phased out the use of so-called phosphate builders. Most phosphoric acid is used to manufacture fertiliser. For example, so-called triple superphosphate fertilisers are manufactured from calcium phosphate-containing rock, such as Ca 3 PO 4 2 , and phosphoric acid:.

The farming of crops depletes soils of essential nutrients, such as phosphate and nitrate, which are replenished by applying fertilisers containing suitable inorganic compounds. Consequently, eutrophication from excess phosphate and nitrate in rivers and lakes remains an issue but now often occurs due to water run-off from agricultural land.

Figure 10 shows the excessive algal growth in the Mediterranean arising from excess nutrients in the water. For example, agricultural practices are altered to minimise pollution from applying nutrients to soils. Phosphate can be removed from water by precipitation with lime, Ca OH 2 , forming hydroxyapatite Equation 20 , the same material which comprises bone and teeth:. Phosphate is recovered from wastewater during chemical sewage treatment, often as struvite, NH 4 MgPO 4.

Phosphate can also be recovered during biological water treatment where it is used in the growth of cell membranes, a process which ultimately forms biological solids or so-called sludge which can be used as a fertiliser. Many p-block elements form oxoacids but here the focus will be on those of phosphorus with a few illustrative examples of other elements. The chemistry of phosphorous compounds in natural water and the body is not quite as simple as it has been treated so far, so the topic will be expanded upon here.

For instance, there are several oxoacids of phosphorus. Table 3 lists other names for these acids. Some acids are polyprotic or taking the alternative viewpoint polybasic meaning they ionise stepwise, unlike hydrochloric acid, HCl, which is a monoprotic acid.

Note only the protons attached to oxygen are ionisable. Phosphoric acid is triprotic undergoing three successive ionisations:.

As phosphoric acid is triprotic, it can form three series of salts with a metal such as sodium: the dihydrogen phosphate, the hydrogen phosphate and the normal phosphate. Note one of the hydrogen atoms in H 3 PO 3 is directly attached to the phosphorus and consequently does not undergo ionisation. An acid is transformed to its conjugate base by losing a proton and vice versa. A large variety of phosphorus acids are derived from 'polyacids', which contain two or more acidic phosphorus centres see Section 3.

Oxoacids by definition contain a covalent AO-H bond, which can dissociate to give a proton and an oxoanion:. There may also be one or more terminal oxygen atoms, so the general formula of oxoacids is A O t OH n , where t can equal 0. These covalent hydroxo compounds have available a wide range of structural possibilities, which is the reason for the existence of a relatively large number of oxoacids.

The variables are as follows:. Traditionally oxoacid formulas are written with hydrogen first, which conceals the fact that hydrogen is often bonded to oxygen. The nomenclature is further complicated by the fact that the inorganic acids and their organic derivatives also have different common names; for instance, phosphorous acid in inorganic chemistry becomes phosphonic acid for its organic derivatives.

To help you through this topic the prefixes and suffixes are in bold italics and the most common name is always used. If more than two oxidation numbers are involved, the prefixes per - and hypo - are used as well:. Oxoanions derived from - ic acids are given the ending - ate and from - ous acids are given the ending - ite.

Additionally, the prefix cyclo- or catena- distinguish cyclic from linear condensed anions, respectively. For an element in its highest oxidation number and sometimes others , it is possible to predict the formula of its orthoacid from its coordination number considerations. The condensed oxoacid formulas are then easily derived by subtracting the appropriate number of water molecules. Third and fourth-row elements prefer four-coordination in their oxoanions.

Thus, the formula of the corresponding neutral oxoacid is H 3 PO 4. The above arguments often fail to predict the formulas of oxoacids of elements in lower oxidation numbers, because the preferred coordination number is either not achieved, or is achieved only by formation of a direct link between the central atom and hydrogen. The tendency for an oxoacid to polymerise by condensation is most marked in the less acidic more highly hydroxylated acids.

Consequently there are many stable condensed forms of silicic and boric acid which are found in minerals. Condensation is most marked in structures where the charge on the uncondensed anion is high, because it is able to reduce the charge density on the anion. In the monomer there are four negative charges for four oxygen atoms; in the dimer there are six negative charges and seven oxygen atoms; in the trimer Structure 8 there are eight negative charges and ten oxygen atoms.

In the limiting case of the infinite polymer, there are two negative charges to every three oxygen atoms. This is the structural unit found in the pyroxene minerals Figure Here shared SiO 4 tetrahedra can be assembled into chains, double chains, sheets, rings and three-dimensional networks to give an amazing variety of structures for crystalline silicate minerals.

The phosphates, unlike the silicates, contain a central atom with a maximum valency of five. Condensed phosphates can be formed if phosphoric oxide is treated with limited amounts of water; or by dehydrating phosphorus oxoacids or their salts by heating. Two molecules of phosphoric acid can condense by loss of a water molecule; the two tetrahedra share one oxygen, giving an acid of formula H 4 P 2 O 7 , known as 'pyrophosphoric', or more correctly diphosphoric acid.

In practice, this can be obtained by heating phosphoric acid 'pyro' comes from the Greek word for fire. Continuation of this process gives triphosphoric acid, H 5 P 3 O 10 , and, eventually, chain polymers called metaphosphoric acids, which contain repeating [HPO 3 ] units. In Figure 13 the ring polymers which are also shown are also called metaphosphoric acids.

The P-O-P link in polyphosphates is readily hydrolysed; in excess water, metaphosphates revert to orthophosphate. So, unlike the condensed silicates, polyphosphates are never found as minerals. The hydrolysis of polyphosphates is an important source of energy within the body Section 3. Sodium polyphosphates are the best known; the general reaction for their formation is the dehydration of sodium dihydrogen phosphate by heating.

The temperature of dehydration controls the nature of the product Figure After deoxyribonucleic acid, DNA which is a phosphodiester , adenosine triphosphate ATP, Structure 10 , is probably the most important phosphorus-containing molecule in the human body. ATP is used to drive many biochemical reactions and cellular processes that require the input of energy; these include cell division and muscle contraction.

The energy input for this reaction comes from the breakdown of organic fuel molecules, such as glucose. Sodium, potassium, magnesium and calcium are found in natural water Table 1. The most important sources of calcium are the mineral deposits of calcium carbonate, CaCO 3 , which are formed from the fossilised remains of long-dead marine organisms.

Examples include the minerals limestone and chalk. Furthermore, this dissolution of calcium carbonate contributes to the hardness of water. Water hardness is often due to the presence of dissolved calcium and magnesium salts.

For instance, calcium hydrogen carbonate upon heating is converted to calcium carbonate. This calcium carbonate is insoluble and deposits in appliances, such as kettles. Human derived acid rain can weather minerals by, for instance, converting calcium carbonate Figure 15 into calcium sulfate, CaSO 4 , leading to harder water. The resulting volume change leads to surface cracking and new conduits for water to percolate. Freezing of this water leads to further damage.

Such acid rain can arise from the combustion of sulfur-containing fuels because this yields sulfur dioxide, SO 2 , which upon oxidation can yield sulfuric acid. Consequently sulfur compounds are removed from fuels before combustion where possible, often using zeolites. Aluminium is a metal forming an aqueous cation, unlike the non-metal boron found above it in Group For example, hydrates of aluminium sulfate, Al 2 SO 4 3 , can be made by dissolving bauxite, Al 2 O 3.

Careful addition of aqueous sodium hydroxide to this solution will first precipitate insoluble aluminium hydroxide:. Both oxide and hydroxide are unusual in being amphoteric. Hence they will first dissolve in and neutralise acids:.

As excess sodium hydroxide is added to the precipitate that is initially formed in Equation 37, the precipitate dissolves to form the tetrahydroxyaluminate ion:.

Note that the bases ammonia and sodium carbonate are not strong enough to cause this dissolution. The Group 1 and Group 2 metals form carbonates, with those of Group 2 being insoluble in water. Aluminium carbonate, Al 2 CO 3 3 , however, cannot be prepared; if aluminium sulfate is added to a solution containing carbonate or hydrogen carbonate ions, Al OH 3 is precipitated and carbon dioxide is evolved:. Figure 17 shows the stages in a typical water treatment process for river water. In stages 1 and 2 chemicals are added and mixed.

Then in stage 3 flocculation or aggregation occurs involving large amounts of aluminium sulfate to clear the water of fine suspensions that are difficult to filter off, such as clay particles. The tiny particles usually carry surface negative charges, which repel each other and so remain in suspension. The positively charged aluminium ions get between the negative particles, counteracting the repulsion and encouraging flocculation.

The water is filtered in stage 5 before disinfection in stage 6 via chlorination. The positively charged alumnium ions get between the negative particles, counteracting the repulsion and encouraging flocculation. Then, when Reaction 42 occurs because of the HCO 3 ions usually present in natural waters, the particles sediment with the precipitate of aluminium hydroxide that forms in the sedimentation tank in stage 4.

Natural water generally requires disinfection before drinking to kill pathogenic or disease-causing microorganisms. Ultraviolet irradiation is one disinfection method and the major chemical disinfectants are ozone and chlorine. These compounds are thought to kill microorganisms by rupturing the cell membrane and reacting with proteins and enzymes within the cells.

Once the chemical structures of proteins and enzymes have been altered they may either fall apart or adopt an unnatural state. Consequently, they fail to perform their roles and so the cell or bacteria dies.

Three of the six water molecules that were attached to the aluminium have been lost, but the other three have acted as proton donors, leaving aluminium associated with hydroxide ions instead of water molecules.

Aluminium minerals such as bauxite are biologically unavailable due to their insolubility in water. In the course of evolution, this would inevitably have limited the bioavailability of aluminium to living organisms.

Aluminium is consequently not an essential element for humans in their normal metabolism. However small amounts of aluminium are found in most people's diet, let us now consider how this might arise?

Aluminum is soluble in both acids and alkalis, dissolving in both hydrochloric acid and sodium hydroxide, liberating hydrogen and finally giving clear, colourless solutions:. Aluminium metal forms a protective oxide film upon exposure to the air and so does not react further. Therefore, as aluminium is fairly inert, it is commonly used in cookware, especially as it is an excellent conductor of heat. How might aluminium in cookware be solubilised? Also, consider if aluminium III is a hard or a soft cation.

Aluminium can be solubilised from cookware by heating acidic solutions, such as those containing citric acid, Structure Consequently it is bound and solubilised by hard chelating ligands in food such as citric acid.

Aluminium has been associated with several neurodegenerative diseases although its role remains controversial. The World Health Organization sets a tolerable daily intake of aluminium for a 60 kg adult at 60 mg. For most people, the mass actually ingested daily is about 10 mg. This aluminium is mostly excreted in the faeces and is not taken up by the body.

That which passes across the gastrointestinal barrier into the blood stream is dealt with by the kidneys Figure However, there is a small accumulation in the whole body, including the brain and lungs.

There is no doubt that aluminium can damage people with impaired kidney function. The condition called dialysis dementia was first noticed in patients who had received long-term haemodialysis for renal failure. Its symptoms included speech disorders, memory loss, convulsions and seizures, followed, in some cases, by death within a year. The incidence of the disease was highest when the municipal water used in the dialysis contained high concentrations of aluminium.

Aluminium is therefore considered a potential neurotoxin. There is a polymer layer between the glass sheets that provides a "flexible strength" to the glass to keep it from breaking into large, sharp pieces. The advantages of this type of glass in a windshield are pretty obvious.

Links can be found below to check facts and learn more. A magnifying glass. A pint glass with a handle. A terrarium is an easy way to demonstrate the water cycle. The condensation forms on the glass exterior cloud and drops to the plants below rain the plants and soil evaporate the moisture place moisture back into the ambient air which in turn condensates on the glass Log in.

Study now. See Answer. Best Answer. Study guides. Chemistry 24 cards. What happens when an atom gains an electron. Which two elements make up three-fourths of the human body. Why are some people fat and others are not. Is it true that the atmosphere is mostly oxygen. Chemistry 26 cards. What is an example of a physical rather thana chemical change. What are the 3 most common elements found in the human body.

Biology 25 cards. As we notice the glass of water, in this observation we find that the glass also made up of sodium silicate which will give us oxygen ion. And the water which is present in the glass will break into the hydroxyl ion and ion. Therefore, glass of water contains ion and ions.

Biology , Which symbols represent ions found in a glass of water. Answers: 3. Answer from: bryantjorell. Answer from: dimakamal Explanation: As we notice the glass of water, in this observation we find that the glass also made up of sodium silicate which will give us oxygen ion.

Answer from: teamzomaxx Answer from: 15krystall. Answer from: adstone Answer from: Kuwillalean Answer from: Carrchris Answer from: The positively-charged side of the water molecules are attracted to the negatively-charged chloride ions and the negatively-charged side of the water molecules are attracted to the positively-charged sodium ions. Essentially, a tug-of-war ensues with the water molecules winning the match. Water molecules pull the sodium and chloride ions apart, breaking the ionic bond that held them together.

After the salt compounds are pulled apart, the sodium and chloride atoms are surrounded by water molecules, as this diagram shows. Once this happens, the salt is dissolved, resulting in a homogeneous solution.