Chapter 5; Chemical Quantities And Introduction To Chemical Reactions

Question 1

convert 1 mole of atoms to atoms

Answer 1

1 mol of atoms = 6.02 x 10^23 atoms

Question 2

convert 1 mol of molecules to molecules

Answer 2

1 mole of molecules = 6.02 x 10^23 molecules

Question 3

convert 1 mole of formula units to formula units (ions)

Answer 3

1 mole of formula units = 6.02 x 10^23 formula units

Question 4

what describes a mole

Answer 4

• 6.022 x 10^23 items
• the amount of a substance containing the same number of formulas units as there are atoms in 12 g of carbon
• Avogadro’s number of items

Question 5

in any chemical reaction, reactants become […]

Answer 5

products

Question 6

the numbers indicate the ratio of reactant and products.

Answer 6

coefficient / ratios

Question 7

what are chemical changes

Answer 7

also known as chemical reactions, the transformation of elements and/or compounds into different elements and/or compounds
- existing bonds are broken and new bonds are formed

Question 8

atoms, ions, and molecules undergo reactions in […] - number proportions

Answer 8

whole

Question 9

atoms, ions, and molecules are extremely […] and […] to count

Answer 9

small
hard

Question 10

how is molecular mass and formula mass calculated

Answer 10

• atomic masses (periodic table) and
• formula for the compund

Question 11

molecular mass is for […] bonds

Answer 11

covalent

Question 12

formula mass is for […] bonds

Answer 12

ionic

Question 13

what is the units when calculating molecular mass

Answer 13

amu/molecule
e.g. H20
1.008 x 2 = 2.016
16.00 x 1 = 16.00
= 18.016 amu/molecule

Question 14

what Is the mole and Avogadro’s number based on

Answer 14

the number of atoms in 12.00 g of carbon-12
avogados number of particles = 1 mole of those particles

Question 15

the mass of 1 mole of any substance is its

Answer 15

molar mass
e.g. Helium; atomic mass is 4.003 amu, and its molar mass is 4.003 g/mol
e.g. carbon; atomic mass is 16.00 amu, and its molar mass is 16.00 g/mol

Question 16

how to convert moles to mass (grams)

Answer 16

1 mole = […] grams

Question 17

how to calculate percent composition

Answer 17

total mass of element in the compound
__________________________________________
total mass of the compound

x100%
= % composition

Question 18

chemical changes can be observed as;

Answer 18

change in color formation of a solid (called precipitate)
heat being produced
evolution of a gas
noticeable aroma

Question 19

atoms, ions, and molecules are in […] motion

Answer 19

constant

Question 20

what happens at the molecular level when atoms, ions, and molecules collide with each other

Answer 20

• most collisions cause particles to bounce away
• some collisions have enough energy to cause a chemical reaction to occur

Question 21

in a chemical reaction, bonds […] and new bonds are formed as […] are converted into […]

Answer 21

break
reactants
products

Question 22

since reactants and products are different from each other, do they still contain the same atoms

Answer 22

yes

Question 23

what changes in the law of conservation of mass

Answer 23

only the bonds between atoms change

Question 24

the law of conservation of mass states that in […] reactions, atoms are neither […] or […]

Answer 24

chemical
created
destroyed

Question 25

what does s stand for in chemical equations

Answer 25

solids (s)

Question 26

what does l stand for in chemical equations

Answer 26

liquid (l)

Question 27

what does g stand for in chemical equations

Answer 27

gas (g)

Question 28

what does aq stand for in chemical equations

Answer 28

aqueous (aq)
side note; substances that can be dissolved in water

Question 29

whole number […] indicate relative proportions
e.g. 2NO

Answer 29

coefficients

Question 30

what are stoichiometric calculations

Answer 30

• the maximum number of moles of product formed from a given number of moles of reactant and
• the maximum mass of product formed from a given mass of reactant

Question 31

from a balanced equation, the moles of any reactant or product can be calculated from any other reactant or product by using their coefficients to create a […] factor

Answer 31

conversion

Question 32

what are the four types of chemical reactions

Answer 32

combination
decomposition
single replacement
double replacement

Question 33

what are other classifications of chemical reaction

Answer 33

oxidation-reduction (transfer of electrons)
acid base (transfer of H+)
combustion (reaction with elemental oxygen)
reactions with organic compounds

Question 34

what are combination reactions

Answer 34

two elements and/or compounds come together to form one compound
e.g.
A + B -> AB

Question 35

what is a decomposition reactions

Answer 35

a single compound breaks down into two elements and/or compounds
AB -> A + B

Question 36

what is a singe replacement reaction

Answer 36

an element substitutes for an atom in a compound to produce a new compound a new element
e.g.
A + BC -> AC + B

Question 37

what is a double replacement reaction

Answer 37

one atom or group in one reactant substitutes for one atom or group in another reactant to produce two new products, which both contain an atom or group from both reactants
e.g. AB + CD -> AD + CB

Question 38

double replacement reactions that form lower energy solid ionic compounds are called […] reactions. the formation of this solid product ( […] ) is the driving force of the reaction

Answer 38

precipitation
precipitate

Question 39

what is oxidation - reduction reactions transfer electrons

Answer 39

oxidation = loss of electrons
reduction = gain of electrons

Question 40

oxidation and reduction always occur […]

Answer 40

together

Question 41

OIL stands for

Answer 41

oxidation is loss of electrons

Question 42

RIG stands for

Answer 42

reduction is gain of electrons

Question 43

how to identify transfer of electrons when they are not obvious (organic compounds containing mostly C and H atoms)

Answer 43

oxidation; increase in O and/or decrease in H
reduction; decrease in O and/or increase in H