Properties of alkaali.

• Alkali are metallic hydroxides of alkaline metals, which in solution ionize to hydroxyl ions that can bind H to form H2O and thereby can remove hydrogen ion from solution.
• Strong alkalis are those which rapidly and almost completely ionize to hydroxyl ions that quickly remove hydrogen ion from solution.
• Weak alkalis are those which slowly and partially ionize to hydroxyl ions that slowly remove hydrogen ion from solution.
• In fact all alkalis are also regarded as base, but all bases are not alkalis. 

Properties of Base.

• Bases are proton acceptor in aqueous solution.
• Bases may be charged particle or may be without charge.
• Strong bases are those which have greater tendency to accept proton. They bind rapidly and strongly with strongly with proton, so quickly remove from solution.
• Weak bases are those which have very low tendency to accept proton. They bind slowly and weakly with proton, so slowly remove proton from solution.
• Conjugate acid of a base is the acid formed by that base after accepting proton. So conjugate acid of a strong base is weak and that of a weak base is strong.

Properties of Acid.

• Acids are proton donor in aqueous solution.
• Acids are molecules having hydrogen atom and capable to release hydrogen ion in aqueous solution.
• Acids may be the molecular species with positive charge or negative charge or may be without charge.
• Conjugate base of an acid is the remaining anionic part of an acid after removal of proton from that acid.
• Strong acid is the acid which rapidly and completely ionizes into H+ and its conjugate base in solution.
• Weak acid the acid which slowly and partially ionizes into hydrogen ion and its conjugate base in solution.
• For strong acid degree of dissociation and dissociation constant is high with low pK value. Conversely for weak acid degree of dissociation and dissociation constant is low with high pK value.
• In case of strong acid the conjugate base shows less affinity to proton because of which they can rapidly and completely ionize to proton. So conjugate bases of strong acids are weak in nature. On the other hand, in case of weak acid the conjugate base shows strong affinity to proton because of which they partially ionize to proton. So conjugate bases of weak acids are strong in nature. 

What are the properties of colloid?

1. Brownian movement

• It is the continuous, rapid and haphazard movement of colloid particles in solution due to the uninterrupted buffeting on colloid particles provided by solvent molecules.
• It is a sort of perpetual game of molecular billiards.
• It is seen under ultra microscope.

* In fact all particles in solution are in movement, but it is only the  movement of colloid, particles which is uisually perceptible. Movement of particles bigger than colloid is too slow (due to big size) and the movement of crystalloid is too fast (due to small size) to be uisually perceptible. Colloid particles move in a moderate rate because of its moderate size, so its
movement is visible.

2. Tyndall phenomenon (optical phenomenon)

• When a beam of light is passed through a colloidal solution and observed at right angle, the tract of light becomes visible as white line due to the dispersion of light rays by the colloid particles.

* In true solution this phenomenon is not true, so true solution is regarded as optically clear.

3. Electrical phenomenon

• They carry electric charge (Positive or negative)
• They have a definite isoelectric pH at which they behave as zwitter ion, become less soluble and may precipitate out.
• They undergo electrophoresis by which colloid particles are separated from each other.

 4. Surface phenomenon

• Colloid particles have larger surface area per unit mass.
• They show increased phenomenon of adsorption and interfacial tension.

* In true solution there is no surface phenomenon because here there is no separating surface between solute and solvent as it is a homogeneous solution. In suspension there is less (negligible) surface phenomenon because here solutes are very large and. have lower surface area per unit mass.

5. Non dialyzable.
 

6. Salting out.

• Colloid particles can be allowed to precipitate out of solution by adding appropriate salts to the solution.