concentration ratio

(noun)

The proportion of total industry output produced by the largest firms (usually the four largest).

Related Terms

Examples of concentration ratio in the following topics:

  • Market Power

    • Measurement of market power is often accomplished with concentration ratios or the Herfindahl-Hirschman Index (HHI).
    • The concentration ratio is the proportion of total industry output produced by the largest firms (usually the four largest).
    • For monopolies, the four firm concentration ratio is 100 percent, while the ratio is zero for perfect competition.
    • The use of the concentration ratio or the HHI to measure market power is not perfect.
    • A high concentration ratio or large firm size is not the only way to achieve market power.

  • Relative Amounts of Acid and Base

    • The pH of a buffer depends on the ratio [base]/[acid] rather than on the particular concentration of a specific solution.
    • The pH of a buffer depends on the ratio [base]/[acid] rather than on the particular concentration of a specific solution.
    • Therefore, you need only to adjust the ratio of [C2H3O2-]/[HC2H3O2] to get the desired final hydrogen ion concentration.
    • To satisfy the expression, the ratio of [C2H3O2-]/[HC2H3O2] must be 0.36 to 1.
    • The change is minimized if the concentrations of acid and conjugate base are equal.

  • Measures of Variability of Qualitative and Ranked Data

    • The variation ratio is a simple measure of statistical dispersion in nominal distributions.
    • Just as with the range or standard deviation, the larger the variation ratio, the more differentiated or dispersed the data are; and the smaller the variation ratio, the more concentrated and similar the data are.
    • This group is more dispersed in terms of gender than a group which is 95% female and has a variation ratio of only 0.05.
    • Similarly, a group which is 25% Catholic (where Catholic is the modal religious preference) has a variation ratio of 0.75.
    • This group is much more dispersed, religiously, than a group which is 85% Catholic and has a variation ratio of only 0.15.

  • Second-Order Reactions

    • This was done intentionally, because in order to determine the reaction order in A, we need to choose two experimental trials in which the initial concentration of A changes, but the initial concentration of B is constant, so that the concentration of B cancels.
    • We do this by picking two trials in which the concentration of B changes, but the concentration of A does not.
    • Trials 1 and 3 will do this for us, and we set up our ratios as follows:
    • Note that both k and the concentrations of A cancel.
    • A table showing data for three trials measuring the various rates of reaction as the initial concentrations of A and B are changed.

  • Weak Acids

    • Therefore, the concentration of H+ ions in a weak acid solution is always less than the concentration of the undissociated species, HA.
    • The equilibrium concentrations of reactants and products are related by the acid dissociation constant expression, Ka:
    • In this case, you can find the pH by solving for concentration of H+ (x) using the acid's concentration (F) and Ka.
    • Assume that the concentration of H+ in this simple case is equal to the concentration of A-, since the two dissociate in a 1:1 mole ratio:
    • Although it is only a weak acid, a concentrated enough solution of acetic acid can still be quite acidic.

  • Redox Titrations

    • Redox titration determines the concentration of an analyte containing either an oxidizing or a reducing agent.
    • What is the concentration of the analyte?
    • We know from our balanced equation above that permanganate and iron react in a 1:5 mole ratio.
    • From the balanced equation, Fe2+ and KMnO4 react in a 5:1 mole ratio.
    • Calculate the concentration of an unknown analyte by performing a redox titration.

  • Basic Principles of Gas Exchange

    • Gas exchange during respiration occurs primarily through diffusion: a process in which transport is driven by a concentration gradient and molecules will move from a region of high concentration to a region of low concentration.
    • Partial pressure (P) is a measure of the concentration of the individual components in a mixture of gases.
    • The various factors that affect gas exchange include oxygen, carbon dioxide, and the ventilation/perfusion (V/Q) ratio.
    • The adequacy of pulmonary gas exchange relies on the V/Q ratio (ventilation/perfusion ratio).

  • First-Order Reactions

    • A first-order reaction depends on the concentration of one reactant, and the rate law is: $r=-\frac{dA}{dt}=k[A]$ .
    • A first-order reaction depends on the concentration of only one reactant.
    • As usual, k is the rate constant, and must have units of concentration/time; in this case it has units of 1/s.
    • We can then run the reaction a second time, but with a different initial concentration of N2O5.
    • We can now set up a ratio of the first rate to the second rate:

  • Equilibrium Constant Expression

    • The equilibrium constant is an expression that gives the ratio of reactants and products at equilibrium.
    • The law of chemical equilibrium states that, at any given temperature a chemical system reaches a state in which a particular ratio of reactant and product activities has a constant value.
    • The activity of X is equal to the concentration of X if it is a gas or liquid.
    • By convention, the equilibrium concentrations of the substances appearing on the right hand side of the chemical equation (the products) are always placed in the numerator of the equilibrium constant expression; the concentrations of the substances appearing on the left hand side of the chemical equation (the reactants) are placed in the denominator.
    • The equilibrium constant,denoted by K, is the ratio of products to reactants at equilibrium.

  • Strong Acid-Strong Base Titrations

    • An acid-base titration is used to determine the unknown concentration of an acid or base by neutralizing it with an acid or base of known concentration.
    • Using the stoichiometry of the reaction, the unknown concentration can be determined.
    • The other reactant of known concentration remains in a burette to be delivered during the reaction.
    • The mole ratio between HCl and NaOH in the balanced equation is 1:1.
    • Step 3: Calculate the molar concentration of HCL in the 25.00 mL sample.