Earlier we learned the a homogeneous mixture of two or much more substances is dubbed a solution. If one of the substances is present in much greater quantities than all the other substances then it is called the solvent. The other substances in equipment are well-known as solutes. Because that example, when a tiny amount the NH4Cl is dissolved in a big quantity that water we refer to water as the solvent and also NH4Cl together the solute. An additional example is Napthalene (used in mothballs) have the right to be liquified in benzene. In this instance benzene is the solvent and also napthalene is the solute.

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Solutes liquified in water (solvent) are called aqueous solutions. No all substances space soluble in water. Why do some building materials dissolve in water and also others don"t? It has to do v the framework of the water molecule.


Oxygen has a higher attraction because that electrons, therefore the mutual electrons (bonding electrons) spend more time close to oxygen then to either of the hydrogens. This offers oxygen a contempt excess an adverse charge and hydrogen a slightly an ext positive charge.


This unlike charge circulation makes water a polar molecule, and gives water its ability to dissolve compounds. Once an ionic solid disappear in water, the optimistic ends the the water molecule are attracted to the negatively fee anions and also the an adverse ends the the water molecule space attracted to the positively charged cations. For example, when NaCl is dissolved in water us find


So once an ionic substance (salt) dissolves in water, it is damaged up right into individual cations and anions which are surrounded by water molecules. Because that example, once NH4 no 3 is liquified in water it breaks up right into separate ions.


NH4+ and NO3- ions space floating approximately in H2O basically independent of each other.

Water additionally dissolves non-ionic substances. Because that example, C2H5OH (ethanol) is really soluble in H2O. This is since C2H5OH has actually a polar oh bond that the water molecules favor to hang around.


countless substances execute not dissolve in water and also that is since they space non-polar and do not communicate well through water molecules. A typical example is oil and water. Oil contains molecules that room non-polar, for this reason they perform not dissolve in water.

How do we understand that ionic solids dissolve in water and type cations and also anions that float approximately separately? One clue comes from conductivity experiments. Anions and also Cations have to act as charge carriers in solution. Therefore a systems with liquified ions have to conduct electricity. Let"s look at a few examples. Pure (distilled) water has no dissolved ions. Because of this pure water will not conduct electricity. In a simple conductivity experiment as shown listed below we would not intend the light to be on.

An aqueous NaCl solution, however, will have dissolved ions present and therefore will certainly conduct electricity. Therefore the irradiate in our conductivity experiment will be ~ above if dipped in an aqueous NaCl solution.

NaCl ionizes totally when liquified in water. It"s advantageous to think the this process as two steps:

Substances the exist in solution almost fully as ions are called solid electrolytes.

Substances that perform not kind ions when they dissolve in water are called non-electrolytes. And example that a non-electrolyte is sugar. Sugar will conveniently dissolve in water however doesn"t type cations and also anions in solution. The is, there room no charge carriers formed.

Substances that just partially ionize into ions when dissolved in water are dubbed weak electrolytes. Because that example, Acetic acid (HC2H3O2) dissolves in water, however only partly dissociates into ions.

Be mindful not to confuse just how soluble a problem is in water through whether it is a weak, strong, or non-electrolyte. For example, sugar dissolves completely in water however it is a non-electrolyte. An additional example are salts that have the right to be really insoluble in water yet the little amount that salt the does dissolve in water is a strong electrolyte.

Homework native Chemisty, The central Science, 10th Ed.

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4.1, 4.3, 4.5, 4.7, 4.9, 4.11, 4.13, 4.15, 4.17, 4.33, 4.35, 4.37,

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