Many ionic and covalent compounds dissolve well in water. This is because of what?

Many ionic and covalent compounds dissolve well in water. This is because..

a. the temperature of liquid water is high enough to allow anything to mix well with its fast moving particles.

b. The air pressure above the water is greater than the pressure exerted by the moving water particles.

c. the solute particles are small enough to fit in the spaces between the tightly packed solvent particles.

d. the attraction between the solute and solvent is about as strong as the attraction between the solvent particles.

1 Answer

  • it should be D

    sorry for my poor English, I’m not from Canada

    In order to dissolve sth.

    these things will happen

    1. solvent – solvent attractions are broken down

    2. solute – solute attractions are broken down

    3. solute – solvent attractions are built up

    To let this occurs

    the solute – solvent attraction should be the strongest force among solvent-solvent; solute-solute ; solute solvent or at least similar strength

    As water is a polar solvent

    sth can dissolve in water should be able to form Hydrogen bond wif solute molecules

    sth which is polar are also can be slightly soluble

    for example carboxylic acid (-COOH) can form extensive hydrogen bond with water, it is soluble in water then.

    On the contrary, Alkane is neither polar nor hydrogen-bond-forming molecules, it do not dissolve in water.

    (this is the case of covalent compound

    ——————–

    (ionic compound

    all ionic compound are soluble in water

    there are mainly 5 steps for the dissolution process

    ionic compounds adopt giant ionic structure

    cations and anions are alternatively held together by non-directional electrostatic force ( ionic bond)

    Water is a kind of polar molecule, there are permanent dipole moment acting on it. H atoms carry a slightly positive charge while O atoms carry slightly negative charge.

    attraction between H atoms in water molecules and anions in the ionic compound,attraction between O atoms in water molecules and cationsin the ionic compound are stronger than the ionic bond.

    Therefore, cations and anions are pulled away from the ionic lattice and dissolved in water

    ————-

    Make a little conclusion for the concept

    1. ionic compound : cations <–ionic bond–> anions

    2. Water: H2O : H(slightly +ve) ; O(slightly -ve)

    3. H2O’s O<–attraction–>cations <–ionic bond–> anions<–attraction–>H2O’s H

    4. attraction > ionic bond

    5. structure of ionic compound is broken down!

    * finally product will be… =>H2O’s O<–attraction–>cations & anions<–attraction–>H2O’s H

    to sum up

    the major factor is the solute-solvent attraction is strong enough => soluble

    hope can help

    Meteor from H.K.

    Source(s): myself~

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