Ch 7 Section 2 Flashcards Preview

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Flashcards in Ch 7 Section 2 Deck (24):
1

the charges on the ions composing an ionic compound reflect

the electron distribution of the compound

2

in order to indicate the distribution of electrons among the bonded atoms in a molecular compound/polyatomic ion,

oxidation numbers (oxidation states), are assigned to the atoms composing the compound/ ion

3

unlike ionic charges, oxidation numbers do not have an

exact physical meaning.

4

oxidation numbers are useful in

naming compounds, writing formulas, and balancing chemical equations.

5

as a general rule in assigning oxidation numbers, shared electrons are assumed to belong to

the more electronegative atom in each bond

6

(Rules for determining oxidation numbers) the atoms in a pure element have an oxidation number of

zero

7

(Rules for determining oxidation numbers) the more-electronegative element in a binary molecular compound is assigned the number equal to the

negative charge it would have as an anion

8

(Rules for determining oxidation numbers) the less-electronegative atom is assigned the number equal to the

positive charge it would have as a cation

9

(Rules for determining oxidation numbers) fluorine has an oxidation number of

-1 in all of its compounds because it's the most electronegative element.

10

(Rules for determining oxidation numbers) oxygen has an oxidation number of -2 in almost all compounds. Eceptions include when it is in

peroxides in which its ox # is -1, and when it's in compounds with fluorine, in which its ox# is +2

11

hydrogen has an ox number of +1 in all compounds containing elements that are

more electronegative than it; it has an ox # of -1 in compounds with metals

12

(Rules for determining oxidation numbers) the algebraic sum of the oxidation numbers of all atoms in a neutral compound is

equal to zero

13

(Rules for determining oxidation numbers) the algebraic sum of the oxidation numbers of all atoms in a polyatomic ion is equal to the

charge of the ion

14

(Rules for determining oxidation numbers) rules apply to covalently bonded atoms but oxidation numbers can also be assigned to

atoms in ionic compounds

15

(Rules for determining oxidation numbers) a monatomic ion has an oxidation number equal to the

charge of the ion

16

because the sum of the oxidation numbers of atoms in a compound must be either zero / equal to charge of ion, it is often possible to

assign oxidation numbers when they are not known

17

many nonmetals can have more than

one oxidation number

18

these numbers can sometimes be used in the same manner as ionic

charges to determine formulas.

19

a formula must represent

facts

20

oxidation numbers alone cannot be used to prove the

existence of a compound

21

the stock system is actually based on

oxidation numbers

22

the stock system can be used as an alternative to the

prefix system for naming binary molecular compounds

23

the stock system is more practical for

complicated compounds

24

prefix-based names and stock-system names are still used interchangeably for

many simple compounds