vet-tech-chem-ch-5-quantities-and-reactions

• 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

the number of items in a mole, equal to 6.02 X 10**23

• 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

• 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

a shorthand way to represent a chemical reaction using chemical formulas to indicate the reactants, products and coefficients to show reacting ratios

• 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

a chemical reaction in which the reactants combine to form a single product

a chemical reaction in which a fuel containing carbon and hydrogen reacts with oxygen to produce CO2, H20 and energy

a reaction in which a single reactant splits into 2 or more simpler substances

a reaction in which parts of 2 different reactants exchange places

• a reaction that releases heat
• the energy of the products is lower than the energy of the reactants
• always absorbs energy (feels cold)

• a reaction that releases heat
• the energy of the products is higher than the energy of the reactions
• always gives off energy (feels warm)

the group of ions represented by the formula of an ionic compound

• 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

• 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

• 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")

• 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

• the loss of electrons by a substance
• biological oxidation may involve the addition of oxygen or the loss of hydrogen

• a reaction in which the oxidation of one reactant is always accompanied by the reduction of another reactant
• total process: electrons gained = electrons lost

the substances formed as a result of chemical 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

the initial substances that undergo change in a chemical reaction

• the gain of electrons by a substance
• biological reduction may involve the loss of oxygen or the gain of hydrogen

a reaction in which an element replaces a different element in a compound

• combination
• decomposition
• replacement
• - single
• - double
• combustion
• neutralization - acid + base -> product + water