Principle Procedure And Observation For Preparing Colloidal Solution Of Egg Albumin
We will be learning about the procedure to experiment on this page. This experiment will help us prepare a colloidal solution of egg albumin. Before getting started, let us look at what a colloid solution/mixture is in Chemistry.
Colloidal Solutions
Colloidal Solutions, known as Colloids, are mixtures where, when looked at microscopically, there is a suspension of highly tiny insoluble particles in another substance.
We cannot assume all mixtures to be colloidal. The mixtures where suspended particles do not settle down at the bottom but still get evenly dispersed into another substance can be known as colloids.
We can Classify these Sols Into Two Different Types
Lyophobic Sols: These are 'liquid hating' sols that get very little or no interaction with the dispersed phase and the dispersion medium. The dispersed phase in this sol has a slight affinity for the dispersion medium.
Lyophilic Sols: These are the 'liquid loving' sols that attract solvents. Here, the colloidal solution firmly attaches to the dispersed medium and phase.
In the case of the egg albumin that is obtained from eggs, these albumins form a lyophilic sol with cold water. This sol is not affected by any traces of impurities and is stable.
Now, after learning about this concept, let us proceed with the actual procedure in theory:
Aim
The aim is to prepare a colloidal solution (lyophilic sol) of egg albumin
Theory
Lyophilic sol is obtainable from the egg albumin present in the eggs. When we mix the egg's albumin with cold water, we obtain lyophilic sol.
This sol is stable and generally not affected by its impurities.
Egg Albumin's formula is C16H26O5.
Required Apparatus Includes
Beakers (250 ml and 50 ml)
Glass rod
Funnel
Filter paper
Tripod stand
Burner
Distilled water
Wire gauze
Soluble starch (500 ml)
pestle and mortar
Porcelain dish
Procedure
The first step is to break down the outer shell of the particular egg with the help of the glass rod from our Apparatus.
Color the colorless liquid (albumin water) and the yellow part and decant the colorless liquid into another beaker.
In the beaker of 250mL, prepare 100mL of the NaCl solution of 5% (w/v).
Pipette on the albumin and start pouring it into the beaker that contains sodium chloride solution. Mix this by constantly stirring for 15 to 20 minutes, ensuring that the sol is prepared well and egg albumins in water forms.
Hence, filter the contents of the beaker with the help of filter paper, a funnel, and a label to filtrate as much as possible.
Precautions
The Apparatus should be adequately cleaned for conducting these experiments.
Now separate the egg albumin water and the yellow yolk before mixing it with sodium chloride solution.
After this, we have to stir the mixture constantly in the beaker and also add the egg albumin to prepare our egg albumin sol.
We will have to make sure that the preparation of egg albumin sol is done at room temperature because the precipitation of the egg albumin will take place in a hot solution.
We should use distilled water to prepare the egg albumin sol. (Colloid is formed in the water when there is a presence of Egg albumin in it)
More About the Colloidal Solution of Egg Albumin
In this article, we will discuss the procedure to perform an experiment that will help us understand how to prepare a colloidal solution of Egg albumin. Before starting the experiment let’s first understand What is a colloid mixture or colloidal solution in Chemistry?
Colloidal solutions or Colloids are the mixtures in which microscopically insoluble particles of one substance are suspended in another substance. Not all the mixtures are colloids. The mixture where suspended particles don’t settle down at the bottom but get evenly dispersed into another substance. The size of the colloids ranges from 1 nm to 1000 nm. One important class of colloidal systems is sols. In sols, the dispersed phase is a solid medium, and the dispersion medium is liquid in the state, and depending upon the nature of the interaction between the dispersed phase and dispersion medium sols can be broadly classified into two types.
Lyophilic Sols: The term lyophilic means ‘liquid-loving’ or ‘solvent- attracting’, which means in this colloidal solution there is a strong affinity towards the dispersed phase and the dispersion medium.
Lyophobic sols: The term lyophobic means ‘liquid-hating’, which means in these sols, there is little or no interaction between the dispersed phase and the dispersion medium i.e., a dispersed phase has little affinity for dispersion medium.
Egg albumin obtained from eggs form a lyophilic sol with cold water. The sol is stable in nature and not affected by the presence of traces of impurities. Now let’s discuss the procedure.
Additional Information
The standard method we can classify a colloid is based on the phase at which our substance disperses and our dispersion medium. Some colloids are emulsion, sol, gel, foam, and aerosol.
Sol is a colloidal system. In this system, the dispersed phase is solid, whereas the dispersed medium is liquid—for example, Paint, Mud, Blood, Ink.
An emulsion can be defined as a colloidal system in which the dispersion phase is liquid. The dispersion medium is also a liquid—for example, Salad Dressing, Brewed Coffee, Milk.
Foam is another type of colloidal system where we observe that the dispersed phase is gas, and the dispersion medium is solid or liquid—for example, Whipped Cream, Bubble Bath, Fire Retardant.
Aerosol is a colloidal system with the dispersed phase being a liquid or solid. The dispersion medium is gas—for example, Perfume, Hairspray, Mist, Fog.
The gel is a colloidal system with a solid dispersion phase and a liquid dispersion medium—for example, Cheese, Jam, Rubber, Gelatin, Toothpaste.
FAQs on To Prepare Colloidal Solution Of Egg Albumin In Chemistry Practical
1. What is a colloidal solution of egg albumin?
A colloidal solution of egg albumin is a heterogeneous mixture in which fine particles of albumin protein are dispersed uniformly in water without settling down. In this system:
- The dispersed phase is egg albumin (protein).
- The dispersion medium is water.
- Particle size lies between 1–1000 nm, typical of colloids.
2. How do you prepare a colloidal solution of egg albumin in the laboratory?
A colloidal solution of egg albumin is prepared by dispersing egg white in distilled water and filtering to remove impurities. The standard laboratory steps are:
- Take the white of a fresh egg and separate it from the yolk.
- Add a small amount of distilled water and stir gently to form a uniform mixture.
- Filter the mixture through muslin cloth or filter paper to remove insoluble impurities.
- Collect the clear filtrate, which is the colloidal solution of egg albumin.
3. Why is distilled water used to prepare egg albumin colloidal solution?
Distilled water is used to prepare egg albumin colloidal solution because it is free from dissolved salts that can coagulate the protein. Salts containing ions such as Na+ or Cl- may reduce the stability of the colloid by neutralizing charges on protein particles. Using distilled water ensures:
- Better colloidal stability
- Prevention of premature coagulation
- Accurate experimental observations
4. What type of colloid is egg albumin in water?
Egg albumin in water forms a sol, specifically a protein sol, where a solid is dispersed in a liquid medium. In this colloidal system:
- The dispersed phase (albumin) behaves like a solid.
- The dispersion medium is liquid water.
5. What are the properties of a colloidal solution of egg albumin?
A colloidal solution of egg albumin shows typical colloidal properties such as Tyndall effect and stability against sedimentation. Its main properties include:
- Shows Tyndall effect (scattering of light).
- Particles do not settle under gravity.
- Cannot be separated by ordinary filtration.
- Exhibits Brownian motion.
6. How can you test the Tyndall effect in egg albumin colloidal solution?
The Tyndall effect in egg albumin colloidal solution is tested by passing a beam of light through the solution and observing light scattering. The steps are:
- Place the colloidal solution in a dark room.
- Pass a strong beam of light through the solution.
- Observe a visible cone of light due to scattering by colloidal particles.
7. Why does egg albumin form a colloid instead of a true solution?
Egg albumin forms a colloid instead of a true solution because its protein molecules are large enough to fall within the colloidal size range of 1–1000 nm. Unlike true solutions:
- Protein molecules are too large to dissolve at the molecular or ionic level.
- They remain dispersed as colloidal particles.
- They scatter light and cannot pass through semipermeable membranes easily.
8. What precautions should be taken while preparing egg albumin colloidal solution?
Precautions during preparation of egg albumin colloidal solution ensure stability and purity of the colloid. Important precautions include:
- Use only fresh egg white.
- Use distilled water to avoid coagulation by salts.
- Stir gently to prevent foam formation.
- Filter properly to remove insoluble impurities.
- Prepare the solution fresh before the experiment.
9. What happens when an electrolyte is added to egg albumin colloidal solution?
When an electrolyte is added to egg albumin colloidal solution, the colloid may coagulate due to neutralization of charges on protein particles. Electrolytes provide ions that:
- Reduce electrostatic repulsion between colloidal particles.
- Cause particles to aggregate.
- Lead to coagulation or precipitation of albumin.
10. What is the difference between a true solution and egg albumin colloidal solution?
The main difference is that a true solution has particle size less than 1 nm, while egg albumin colloidal solution has particles in the range of 1–1000 nm. Key differences include:
- Particle size: True solution < 1 nm; Colloid 1–1000 nm.
- Tyndall effect: Absent in true solution; Present in egg albumin colloid.
- Filtration: True solutions pass through filter paper and membranes; colloids pass through filter paper but not semipermeable membranes easily.
- Appearance: True solution is completely transparent; colloid is translucent.
