1. Activation energy
    • the energy needed upon collision to break apart the bonds of the reacting molecules
    • energy needed to break apart bonds in order to be able to form new bonds
  2. Avogadro's number
    the number of items in a mole, equal to 6.02 X 10**23
  3. Balanced equation
    • the final form of a chemical equation that show the same number of atoms of warch element in the reactants and products
    • helpful hints:
    • - use the correct formula; H2O /= H2O2
    • - construct a tally table under the yields sign
    • - change only the coefficients, never the subscripts
    • - Balance O's, H's, and single elements last
    • - use fractional coefficients in front of diatomic molecules (H2, N2, O2 & all Group VII) to help balance the equation. Clear the fraction by multiplying the entire equation by the appropriate denominator
    • - keep polyatomic ions intact in tally table only if there is no evidence of their decomposition during the reaction
  4. Catalyst
    • a substance that increases the rate of reaction by lowering the activation energy
    • a substance that lowers the activation energy and is not ultimately consumed by the reaction
  5. Chemical equation
    a shorthand way to represent a chemical reaction using chemical formulas to indicate the reactants, products and coefficients to show reacting ratios
  6. Coefficients
    • whole numbers placed in front of the formulas to balance the number of atoms or moles of atoms of each element on both sides of the equation
    • number placed in front of the total of a substance which tell how many molecules, units or moles are needed in the chemical reaction
  7. Combination reaction
    a chemical reaction in which the reactants combine to form a single product
  8. Combustion reaction
    a chemical reaction in which a fuel containing carbon and hydrogen reacts with oxygen to produce CO2, H20 and energy
  9. Decomposition reaction
    a reaction in which a single reactant splits into 2 or more simpler substances
  10. Double replacement reaction
    a reaction in which parts of 2 different reactants exchange places
  11. Endothermic reaction
    • a reaction that releases heat
    • the energy of the products is lower than the energy of the reactants
    • always absorbs energy (feels cold)
  12. Exothermic reaction
    • a reaction that releases heat
    • the energy of the products is higher than the energy of the reactions
    • always gives off energy (feels warm)
  13. Formula unit
    the group of ions represented by the formula of an ionic compound
  14. Mass calculations for reactions
    • periodic table is used when:
    • - changing g -> moles
    • - changing moles -> g
    • - ID does not change
    • balanced equation is used when:
    • - mole -> mole
    • - ID does change
  15. Molar mass
    • the mass in grams of 1 mole of an element
    • equal numerically to the atomic mass, molecular mass, atomic weight, and molecular weight
    • in a compound, equal to the sum of the masses of the elements multiplied by their subscripts in the formula
    • triple equality from periodic table: 1 mole H2O = 6.02 x 10**23 molecules of H2O = 18.0 g H2O
  16. Mole
    • a group of atoms, molecules or formula units that contains 6.02 x 10**23 of these items
    • number = 6.02 x 10**23 of anything (comparable to "dozen" or "ream")
  17. Mole-mole factor
    • a conversion factor that relates the number of moles of 2 compounds derived from the coefficients in an equation
    • e.g. sucrose = C12H22O11; 12 mole C / 1 mole sucrose or 1 mole sucrose / 12 mole C
  18. Oxidation
    • the loss of electrons by a substance
    • biological oxidation may involve the addition of oxygen or the loss of hydrogen
  19. Oxidation-reduction reaction
    • a reaction in which the oxidation of one reactant is always accompanied by the reduction of another reactant
    • total process: electrons gained = electrons lost
  20. Products
    the substances formed as a result of chemical reaction
  21. Rates of reaction
    • rate may be speeded up by:
    • - increasing the temperature (increases the motion of the molecules)
    • - increasing the concentration of reactants (making them more likely to interact)
    • - adding a catalyst
  22. Reactants
    the initial substances that undergo change in a chemical reaction
  23. Reduction
    • the gain of electrons by a substance
    • biological reduction may involve the loss of oxygen or the gain of hydrogen
  24. Single replacement reaction
    a reaction in which an element replaces a different element in a compound
  25. Types of chemical reactions
    • combination
    • decomposition
    • replacement
    • - single
    • - double
    • combustion
    • neutralization - acid + base -> product + water
Card Set
vet tech chemistry quantities and reactions set