Unit 4 Key Terms and Concepts Flashcards Preview

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Flashcards in Unit 4 Key Terms and Concepts Deck (42)
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1

Formula Unit

an atom, a molecule, an ion, or a
combination of cations and anions that gives a
balance of charges. Anything represented by a
chemical formula.

2

a Chemical Equation

uses chemical symbols to
represent what happens in a chemical reaction.

3

(s)

Solid State

4

(aq)

aqueous (dissolved in water) state

5

(l)

liquid state

6

(g)

gas state

7

coefficients

indicate how many of the chemical units participate in the reactions

8

balanced chemical equation

has the same number of atoms of each kind on both sides of the reaction

9

Law of Conservation of Matter

matter is not
created or destroyed in chemical reactions. Mass
of products = mass of reactants.

10

decomposition reaction

one substance splits into two or more simpler substances

11

Combustion reaction

a reaction of a substance
with O2 that produce heat and light and oxide products. (CO2 and H2O)

12

1 amu=

1.6605387 x 10−24 g

13

proton mass

1.007 amu

14

neutron mass

1.008 amu

15

Average atomic mass (atomic weight)

the weighted average mass of naturally occurring
isotopes in a sample expressed in amu’s.

16

Formula mass (formula weight)

the sum of the average atomic masses (atomic weights) of all the atoms in a formula unit. The mass of a compound in amu’s

17

Percentage composition

is the percentage of each element in a compound by mass.

18

percent composition equation

% element A = mass from element A/(total compound mass) x 100

19

1 mol=

6.022 x 1023 formula units

20

mole (mol)

an amount of substance containing
the same number of formula units as there are
atoms in 12.000 g of ^12C.

21

molar mass

the mass in grams of one mole of a
substance. Numerically equal to formula weight.

22

The formula mass of water

2(1.008) + 16.00 = 18.02 amu

23

The molar mass of water

2(1.008) + 16.00 = 18.02 g/mol

24

The mole is the SI unit for

an amount of substance

25

Molecular Formula

The actual numbers of atoms or moles of each element in a compound

26

empirical formula

a chemical formula that gives the smalles whole number ratios of atoms or moles of each element in a compound

27

How do you find the empirical formula from a moleuclar formula?

Reduce the subscripts as much as possible.
ex: C6H12O6= CH2O

28

C6H6 Empirical Formula

CH

29

Na2SO4 Empirical Formula

NaSO2

30

C6H14 Empirical Formula

C3H7