What makes an ionic compound soluble or insoluble?
Ionic compounds dissolve in water if the energy given off when the ions interact with water molecules compensates for the energy needed to break the ionic bonds in the solid and the energy required to separate the water molecules so that the ions can be inserted into solution.
Are ionic lattices soluble in water?
Most ionic compounds are soluble in water and form aqueous solutions.
How does lattice structure affect solubility?
If the lattice energy (cost) is larger than the energy of solvation of the ions (gain) the compound won’t dissociate, and it will be insoluble. There is a large grey area where lattice energy and solvation energy are close, and for those compounds temperature has a big influence on solubility.
Why are some ionic compounds more soluble than others?
If the water molecules have a greater attraction to the ions than ions have for each other, then the compound will be soluble in water. Compounds with small ions are less soluble than compounds with large ions. Small ions are closer to each other, so they have strong attractive forces.
Why ionic compounds are insoluble in water?
Ionic compounds consist of a positive cation and a negative anion. This is because the ionic forces in those molecules are very high, which creates high lattice energy. Due to high lattice energy, the hydration energy decreases that makes those compounds insoluble in water.
How do you tell if a compound is soluble or insoluble?
Solubility Rules
- Salts containing Group I elements (Li+, Na+, K+, Cs+, Rb+) are soluble .
- Salts containing nitrate ion (NO3-) are generally soluble.
- Salts containing Cl -, Br -, or I – are generally soluble.
- Most silver salts are insoluble.
- Most sulfate salts are soluble.
- Most hydroxide salts are only slightly soluble.
Why do ionic lattices dissolve in water?
Ionic compounds dissolve in water due to the difference between its lattice energy and its hydration energy.
Why are ionic lattices soluble in water?
Most ionic compounds are soluble in water. Polar water molecules have a strong attraction for charged ions and the charged ions become solvated as they dissociate into the water and ionic compounds are soluble in water.
How does lattice energy affect solubility of ionic compounds?
The lattice energy of a salt therefore gives a rough indication of the solubility of the salt in water because it reflects the energy needed to separate the positive and negative ions in a salt. Sodium and potassium salts are soluble in water because they have relatively small lattice energies.
How does lattice energy affect solubility in water?
If there is a net release of energy, that is, if more energy is released on hydration than is stored in the ionic solid lattice, then solubility is favored. If there is a net gain of energy, that is, if less energy is released on hydration than is stored in the ionic solid lattice, then solubility is unfavored.
How is lattice energy related to solubility?
Is molecular or ionic more soluble?
In summary, covalent compounds are softer, have lower boiling and melting points, are more flammable, are less soluble in water and do not conduct electricity compared to ionic compounds….Physical Properties of Molecular Compounds.
| Property | Ionic Compounds | Molecular Compounds |
|---|---|---|
| Water solubility | Usually high | Variable |
Why are ionic compounds soluble in water?
In water Most ionic compounds are soluble in water. Polar water molecules have a strong attraction for charged ions and the charged ions become solvated as they dissociate into water and ionic compounds are soluble in water.
How does lattice energy affect the solubility of a compound?
However, to pull the ions apart in the first place, there has to be an energy increase to overcome the lattice energy. If the lattice energy (cost) is larger than the energy of solvation of the ions (gain) the compound won’t dissociate, and it will be insoluble.
What happens to the lattice energy when water surrounds an ion?
Since water is very polar, when water surrounds an ion there is a decrease in overall energy. However, to pull the ions apart in the first place, there has to be an energy increase to overcome the lattice energy. If the lattice energy (cost) is larger than the energy of solvation of the ions (gain) the compound won’t dissociate,…
Which solvents are easily soluble in ionic compounds?
Ionic compounds are easily soluble in any liquid that is capable of breaking the ionic bond in them. Water breaks the ionic bond by hydrogen bonding, as, water itself has a more ionic bond and is polar in nature. Many other solvents such as kerosene and petrol are not capable of breaking the ionic bond.