Question

Fill in the blank

1. ________ is responsible for the unusual thermal properties of ammonia?

2.Bicarbonate buffer in blood involves the dissociation of _______.

3. ________ is a rule concerning chemical processes that state that stress applied to a reaction at equilibrium results in the displacement of the equilibrium so as to relieve the stress.

4. The conjugate acid of water is _______.

5. When blood pH rises above 7.45, ______results.

6. A buffer is composed of a weak acid and its _____ base.

7. Osmotically active substances are called ______.

8. A semisolid viscoelastic substance that resists flow and stores mechanical energy is called a ______.

9. The most important ion in biological systems is the ________ ion.

10. The ability of a solution to resist pH changes is called its ______.

Answer 1

2. Bicarbonate buffer in blood involves the dissociation of H₂CO₃:

In aqueous systems, as blood, the bicarbonate ion can catch a proton to produce carbonic acid, according to the equilibrium reaction:

Then, carbonic acid in the blood is dissociated into water and carbon dioxide according to the reaction:

3. Le Chatêlier's principle is a rule concerning chemical processes that state that stress applied to a reaction at equilibrium results in the displacement of the equilibrium so as to relieve the stress.

For a generic chemical reaction in equilibrium:

The expression of the equilibrium constant is given by:

If a disturbance, change or stress is applied, concentrations of the susbtances will change. To mantain a constant value for K, the system in equilibrium must have a displacement in the opposite side of the effect of the changes. This rule is known as Le Chatêlier's principle.

4. The conjugate acid of water is hydronium ion:

Taking into account that water is a weak base, it can catch an acidic proton to form its conjugated acid, according to the equilibrium:

This conjugated acid is called hydronium ion

5. When blood pH rises above 7.45, alkalosis results.

Normal values of pH of blood are in the range of 7.35 - 7.45 units. At a higher pH value, we say that is an alkalyne solution. If blood pH is above of 7.45, the condition is called alkalosis.

6. A buffer is composed of a weak acid and its conjugated base.

According to the Bronsted-Lowry theory of acids and bases, an acid substance can lose a proton to form its conjugated base. This conjugated base is able to catch a proton to form the acid again. It can be expressed by the following equilibrium reaction:

In a buffer solution, the presence of a weak acid and its conjugatedd base is useful to resist the changes in pH of the solution