Chop up the egg whites, add some urea (which just happens to be a chemical found in urine, so these may not be very tasty eggs any more), and dissolve them in water. The urea helps to liquefy the solid egg whites and break down some of the bonds between the proteins.

The major inorganic components of egg white are sulfur, potassium, sodium, and chloride. Phosphorus, calcium, and magnesium are next in importance. Table shows the content of major minerals in eggs (Table 1).

The principal proteins in egg white are albumen (water soluble) and globular proteins (soluble in neutral dilute salt solutions).

The egg is composed of the albumen which is the white part and the vitellus which is the yellow part. The albumen is surrounding the vitellus and contains proteins, which are long chain amino acids. The most important protein is ovalbumine (54 %), which is composed of four amino acid chains and water-soluble.

Eggs get rubbery when they are cooked too long at too high temperatures. Think hard boiled. They have a rubbery texture because the protein in the white part of the egg coagulates during cooking. That texture which is expected in the hard boiled egg, is unpleasant in a scrambled egg.

Is baking a pizza endothermic or exothermic? Baking a pizza is an endothermic process as well. Because the dough absorbs heat.

Melting is an endothermic reaction in which the total amount of heat in the substance, also known as the enthalpy, increases.

This energy breaks down the rigid bonds in the ice, and causes the water molecules to move quicker and collide more often. As a result, the temperature of the ice rises and it turns into water! Basically, melting ice is an endothermic reaction because the ice absorbs (heat) energy, which causes a change to occur.

It requires energy for a solid to melt into a liquid. However, it can be used for both the melting and the solidification processes as long as you keep in mind that melting is always endothermic (so ΔH will be positive), while solidification is always exothermic (so ΔH will be negative).

Exothermic Reactions: Lighting a Match An example of an exothermic reaction is lighting a match. When you strike the match on the match box, the friction generates more heat energy than can be taken in by the surrounding particles. This results in the flame.

Examples of exothermic reactions include combustion reactions, oxidation reactions (such as rusting), and phase transitions from the liquid to solid state.

• any combustion reaction.
• a neutralization reaction.
• rusting of iron (rust steel wool with vinegar)
• the thermite reaction.
• reaction between water and calcium chloride.

Intermetallic and thermite reactions are among the most exothermic. The thermite reaction 10 Nd + 3 I2O5 has a predicted adiabatic reaction temperature of 7580 K. While 2 Ta + I2O5 is 7240 K. On the intermetallic side C + Hf can theoretically reach 4223 K with Q = 1318 j/g.

The most endothermic reactions are entropy driven. In order to absorb heat from the environment, energy must be redistributed in an even less available form than random energy at that temperature. This means it must be given more degrees of freedom, the freedom of more molecular states than before.

Here are some of the examples of exothermic reaction:

• Making of an ice cube. Making ice cube is a process of liquid changing its state to solid.
• Snow formation in clouds.
• Burning of a candle.
• Rusting of iron.
• Burning of sugar.
• Formation of ion pairs.
• Reaction of Strong acid and Water.
• Water and calcium chloride.