Finals Flashcards

Question

sig fig multiplication/division

Answer 1

use # of sig figs in limiting term

Answer 2

the measurement w/ the smallest # of sig figs or decimal places

Answer 3

smallest # of decimal places

Answer 4

how close the measurement is to the true value

Answer 5

a measure of how close the measurements are to each other

Answer 6

defines the relationship b/w diff units Ex: 1 kg = 2.205 lbs

Answer 7

a ratio of the 2 parts of an equivalence statement that relates the 2 units Ex: 1kg/2.205lbs

Answer 8

the process of converting from 1 unit to another choose conversion factor that cancels the units u don't want when cubing/squaring, make sure to cube/square the WHOLE conversion factor

Answer 9

absolute temp scale doesn't use degree notation, just K

Answer 10

depends on quantity of sample measured mass, volume

Answer 11

independent of sample size prop's often characteristic of substance being measured Ex: density, temp, melting & boiling pts

Answer 12

D = m/v g/cm³ or g/mL

Answer 13

|accepted value - experimental value| \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ accepted value x 100

Answer 14

physical chemical

Answer 15

properties that don't involve substances changing into another substance color, odor, taste, feel, density, melting & boiling pts, temp

Answer 16

prop's that involve substances changing into another substance chemical reaction Ex: sugar ferments → alcohol, platinum doesn't react w/ oxygen @ room temp, copper sheets on statue of liberty have green coating

Answer 17

has volume & mass three states: solid, liquid, gas

Answer 18

the amount of space that an object occupies

Answer 19

the amount of matter that an object contains

Answer 20

rigid fixed shape & volume

Answer 21

has definite volume but takes shape of container

Answer 22

no fixed volume/shape takes shape & volume of container

Answer 23

1+ substances r changed into other substances

Answer 24

involves a change in 1+ phys prop's, but no change in the fundamental components that make up the substance most common = changes of state

Answer 25

solid → liquid = melting liquid → solid = freezing liquid → gas = evaporation gas → liquid = condensation gas → solid = sublimation (dry ice) solid → gas = deposition

Answer 26

involves a change in the fundamentel components of the substance a given substance changes into a diff substance/substances

Answer 27

a substance that can't be broken down into other substances by chemical methods microscopic form - sometimes used to mean a single atom of that element macroscopic form - other times used to mean a sample large enough to weigh on a balance generic form - when we say human body contains sodium, doesn't mean elemental sodium is present, rather atoms of some form of sodium 118 elements, 88 of which occur naturally

Answer 28

a substance composed of a given combo of elements that can be broken down into those elements by chem methods

Answer 29

a combo of substances in varying proportions Ex: salt water homogenous/heterogeneous

Answer 30

uniform composition Ex: mixed salt water

Answer 31

non-uniform composition Ex: choc chip cookie, sand & water

Answer 32

will always have same composition element/compound

Answer 33

physical changes distillation filtration

Answer 34

liquid → gas → liquid separates liquids based on boiling pt by condensing vapor used to recover liquids Ex: salt water: solution heated to vaporize(boil) water. water vapor cooled so that condenses back to liquid state & all liquid is collected. after all water vaporized from original sample, pure sodium chloride remains.

Answer 35

separates solids from liquids used to recover solids or liquids Ex: mixture of salt(NaCl) & sand. sand = insoluble in water. add water & dissolve salt. filter so that salt solution passes thru & sand remains on filter. water then evaporated from salt.

Answer 36

separates solids from liquids used to recover solids

Answer 37

water that has been evaporated & condensed to remove impurities

Answer 38

a substance or compound that is added to a system in order to bring about a chemical reaction, or added to see if a reaction occurs

Answer 39

the formation of a solid in a solution during a chemical reaction

Answer 40

new total mass \_\_\_\_\_\_\_\_\_\_\_\_\_\_ original total mass

Answer 41

mass of recovered \_\_ \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ total mass of recovered solids x 100

Answer 42

molarity measure of concentration (moles/liter)

Answer 43

used as abbreviations for element names 3 letters = unknown

Answer 44

* most natural materials are mixtures of pure substances * pure substances are either elements or compounds * law of constant composition * elements are made of atoms * all atoms of a given element r identical * the atoms of a given element r diff from those of any other element * atoms of 1 element can combine with atoms of other elements to form compounds

Answer 45

a distinct substance that is composed of the atoms of 2+ elements and always contains exactly the same relative masses of those elements can be broken down into elements by chem methods always has the same relative #'s & types of atoms

Answer 46

a given compound always contains the same proportion (by mass) of the elements Ex: water always contains 8g of oxygen for each gram of hydrogen

Answer 47

tiny particles of which elements are made indivisible in chem processes not created/destroyed in chem reactions. reaction only change the way the atoms r grouped together

Answer 48

expresses the type of atoms & #'s of each atom in a given compound table salt = NaCl water = H₂O

Answer 49

table salt = sodium chloride

Answer 50

a negatively charged particle located outside of nucleus in a negatively charged "cloud" most of volume of atom

Answer 51

a positively charged particle, same size of charge as an electron, but positive

Answer 52

a neutral particle w/ a mass relatively close to that of a proton

Answer 53

small dense center of atom protons & neutrons most of the mass of the atom

Answer 54

the # and arrangement of the electrons the space in which the electrons move accounts for most of the atomic volume. the electrons r the parts of the atoms that intermingle when atoms combine to form molecules. the # of electrons a given atom possesses greatly affects the way it can interact w/ other atoms

Answer 55

the identity of an element is determined by this the # of protons

Answer 56

(of an element) have the same # of protons, & therefore the same atomic #, but diff #'s of neutrons

Answer 57

the total # of protons & neutrons in an atom used in naming to identify isotopes, such as Carbon-14 & Carbon-12

Answer 58

Iodine-123 = the isotope of choice for nuclear medicine imaging of the thyroid gland, which naturally accumulates all iodine isotopes

Answer 59

good conductors of heat & electricity shiny malleable ductile always form cations; tendency to lose electrons

Answer 60

can be hammered into sheets flattens/bends w/out shattering

Answer 61

can be drawn into wires

Answer 62

good insulators dull appearance most r gases/easily vaporized solids & liquids solids nonmetals r brittle

Answer 63

absorbs electricity

Answer 64

exhibits some prop's of both metals & nonmetals

Answer 65

all elements in a group have similar chem prop's

Answer 66

Alkali Metals

Answer 67

Alkaline Earth Metals

Answer 68

Transition Metals

Answer 69

Noble Gases

Answer 70

cannot stand alone 2 atoms hydrogen, nitrogen, oxygen, flourine, chlorine, bromine, iodine HINClBrOf

Answer 71

an equal # of protons & electrons gives an atom a net zero charge adding or removing an electron from a neutral atom will create a charged ion always formed by adding/removing electrons, not by changing the # of protons

Answer 72

positive ion when atom loses 1+ electrons Na → Na⁺ + e^- named using name of the parent atom Ex: Na⁺ is called the sodium ion

Answer 73

negative ion when an atom gains 1+ electrons Cl + e^- → Cl^- named by taking the root name of the atom & changing the ending (adding -ide)

Answer 74

chlorine - chloide ion flourine - flouride bromine - bromide iodine - iodide oxygen + 2 electrons = oxide sulfur + 2 electrons = sulfide

Answer 75

Group 1 metals → +1 Group 2 metals → +2 many Group 3-12 metals → multiple charges Group 13 metals → +3 Group 16 atoms → -2 Group 17 atoms → -1

Answer 76

whenever a compound is formed b/w a metal & non-metals, it can be expected to contain ions usually formed with metals + nonmetals; when they react, the metal atoms tend to lose 1+ electrons, which r gained by the atoms of the nonmetals; the reactions tend to form compounds that contain metal cations & nonmetal anions chem compounds must have net charge of 0 → must be cations & anions present; the # of cations & anion must result in net charge of zero usually strong electrolytes & can be expected to dissociate completely in solution

Answer 77

the cation/metal/pos. is always written first use subscripts to balance charges on compounds

Answer 78

shatters/cracks into small pieces when struck

Answer 79

a substance that separates into ions when dissolved in water

Answer 80

the process in which ionic ompounds separate into ions

Answer 81

usually non-electrolytes & don't dissociate to form ions resulting solutions don't conduct electricity

Answer 82

can partially/completely dissociate, depending on strength

Answer 83

tungsten 74

Answer 84

composed of 2 elements two classes: 1. metal & non-metal - metal forms only one cation 2. metal & non-metal - the metal can form 2+ cations that have diff charges 3. two non-metals

Answer 85

1. the cation is always named 1st and the anion 2nd 2. a simple cation (obtained from a single atom) takes its name from the **name of the element.** 3. a simple anion (obtained from a single atom) is named by taking the 1st part of the element name(the root) and adding **-ide**

Answer 86

1. cation always named 1st and the anion 2nd 2. because the cation can assume more than one charge, the charge is specified by a Roman numeral in parentheses

Answer 87

1. 1st element in the formula is named first, and the full element name is used 2. the 2nd element is named as though it were an anion 3. prefixes are used to denote the numbers of atoms present 4. the prefix *mono-* is never used for naming the 1st element

Answer 88

charged entities composed of several atom bound together name the cation first and then the anion. use Roman numerals if necessary.

Answer 89

series of ions that contain a given element and different oxygen atoms when there are 2 members in such a series, the one with the smaller amount of oxygen is called -ite and the one with the larger amount of oxygen = -ate. when there are more than two members of a series, hypo- (one less) and per- (one more) are used as prefixes Ex: hypochlorite, chlorite, chlorate, perchlorate

Answer 90

when dissolved in water, certain molecules produce H⁺ ions → acids an acid can have one/more H⁺ ions. the rules for naming acids depends on whether the anion contains oxygen * if the anion doesn't contain oxygen, the acid is named with the prefix hydro- and the suffix -ic attached to the root name for the element. HCl is hydrochloric acid. * when the anion contains oxygen and ends in -ate, the suffix for the acid becomes -ic. H₂SO₄ is sulfuric acid * when the anion contains oxygen and ends in -its, the suffix for the acid becomes -ous. H₂SO₃ is sulfurous acid.

Answer 91

HCl → hydrochloric acid HC₂H₃O₂ → acetic acid H₂SO₄ → sulfuric acid HNO₃ → nitric acid H₃PO₄ → phosphoric acid

Answer 92

when atoms receive energy, they become excited. they can release the energy by emitting a light. the emitted energy is carried away by a **photon** the energy of the photon corresponds exactly to the energy change of the emitting atom high energy photons correspond to short wavelength light. low energy photons correspond to long wavelength light the photons of red light have less energy than the photons of blue light cuz red light has a longer wavelength than blue light

Answer 93

when we study the photons of visible light emitted, we only see certain colors only certain types of photons r produced because only certain protons r emitted, only certain energy changes r occurring so, hydrogen atoms must have certain discrete energy levels we say the energy levels of H r **quantized**, that is, only certain values r allowed energy levels of *all* atoms r quantized

Answer 94

the probability map is called an orbital. the orbital shown in the pic is called the 1s orbital & describes the ground (lowest) state of energy for H size of orbital is defined by a sphere that contains 90% of the total electron probability

Answer 95

discrete energy levels designated by whole #'s symbolized by n; n can equal 1, 2, 3, 4,... level 1 corresponds to n = 1,etc. energy of the level increases as value of n increases describe size & shape. the s orbital is spherical. level 1 is smaller than level 2, which is smaller than level 3. each principal energy level contains 1+ types of orbitals, called **sublevels**

Answer 96

the # of sublevels present in a given principal energy level equals n. e.g. level 1 contains one sublevel (1s); level 2 contains 2 sublevels (2 types of orbitals), the 2s orbital and the three 2p orbitals; and so on these r sumarized in the pic. the # of each type of orbital is shown in parentheses n value always used to label orbitals of a given principal energy level & followed by letter that indicates the type/shape of the orbital

Answer 97

can be empty or can contain 1 or 2 electrons, but never more than 2 if 2 electrons occupy the same orbital, must have opp spins shape of an orbital doesn't indicate the details of electron movement - merely indicates the prob distribution for an electron residing in that orbital

Answer 98

each electron appears to spin like a top on its axis can only spin in 1 direction. we represent spin with up & down arrows

Answer 99

an atomic orbital can hold a max of 2 electrons & those 2 electrons must have opp spins

Answer 100

principal energy level followed by sublevel; # of electrons in the orbital placed as superscript Ex: 1s¹

Answer 101

the electrons in the outermost(highest) principal energy level of an atom these r the electrons involved in bonding of atoms to each other the atoms of elements in the same group have the same # of electrons in a given type of orbital, except that the orbitals are in diff princ energy levels (except He, which is 1s²) elements w/ same valence electron arrangement show very similar chem behavior

Answer 102

in a principal energy level that has *d* orbitals, the *s* orbital from the *next* level fills before the d orbitals in the current level. that is, the (n + 1)s orbitals always fill before the nd orbitals Ex: the 5s orbitals fill for rubidium & strontium before the 4d orbitals fill

Answer 103

after lanthanum, which has configuration [Xe]6s²5d¹ a group of 14 elements corresponds to the filling of the seven 4f orbitals

Answer 104

after actinium, [Rn]7s²6d¹ 14 elements corresponds to the filling of seven 5f orbitals

Answer 105

a force that holds 2+ atoms together & makes them function as a unit in water, the fundamental unit is the H-O-H molecule, which is held together by the two O-H bonds

Answer 106

formed when an atom that loses an electron relatively easily reacts w/ an atom that accepts an electron when metal reacts w/ non-metal resulting bonds = **ionic bonds** electrons transferred

Answer 107

when 2 similar atoms form a bond, the electrons r equaly attracted to the nuclei of the 2 atoms electrons shared by nuclei Ex: diatomic hydrogen H-H

Answer 108

b/w the extremes atoms r not so diff that electrons r transferred, but diff enough that unequal sharing of the electrons results

Answer 109

the unequal sharing of electrons b/w 2 atoms is described by this property the relative ability of an atom in a molecule to attract shared electrons to itself the higher the electronegativity value, the closer the shared electrons tend to be to that atom when it forms a bond F has highest electronegativy & so always forms polar bonds increasing electronegativity as goes right and up on periodic table

Answer 110

depends on the diff b/w the electronegativity values of the atoms forming the bonds if similar electronegativities, the electrons r shared almost equally & bond shows little polarity if very diff electronegativities, very polar bond is formed

Answer 111

representative (main-group) **metals** form ions by losing enough electrons to attain the configuration of the **previous noble gas** that occurs before the metal **nonmetals** form ions by gaining enough electrons to attain the configuration of the **next noble gas** when a non-metal and a Group 1, 2, or 3 metal react to form a binary ionic bond, the ions form so that the non-metal completes the valence-electron config of the next noble gas & the metal empties the valence orbitals to achieve the config. of the prev. noble gas when 2 non-metals react to form a covalent bond, share electrons in a way that completes the valence-electron configuration of both atoms

Answer 112

bonding involves jsut the valence electrons. this structure is a representation of a molecule that shows how the valence electrons r arranged among the atoms in a molecule H - duet rule He - doesn't form bonds cuz valence orbital already filled 2nd row nonmetals C thru F - octet rule Ne - doesn't form bonds cuz already has an octet of valence electrons 1. obtain sum of the valence electrons from all of the atoms 2. use 1 pair of electrons to form a bond b/w each pair of bound atoms. use line. 3. arrange the remaining electrons to satisfy the duet rule for hydrogen & the octet rule for each 2nd-row element (may need to guess & check w/ double bonds, etc.)

Answer 113

H forms stable molecules where it shares only 2 electrons

Answer 114

2nd-row nonmetals C through F form stable molecules when r surrounded by enough electrons to fill the valence orbitals - that is, the one 2s and the three 2p orbitals 8 electrons required to fill these orbitals

Answer 115

noble gas valences from top to bottom: 1s² 2s²2p⁶ 3s²3p⁶ 4s²4p⁶ 5s²5p⁶ 6s²6p⁶

Answer 116

color change formation of a precipitate (solid) formation of a gas (bubbles) heat is produced (exothermic) **or** heat is absorbed (endothermic)

Answer 117

reactants → products

Answer 118

in a chemical reaction, atoms r neither created nor destroyed thr must be the same # of atoms on the reactant side of the equation as there are on the product side of the equation

Answer 119

g - gas l - liquid s - solid aq - aqueous

Answer 120

precipitation reactions (driving force = formation of precipitate) gas-forming reactions (driving force = formation of a gas) acid-base reactions (driving force = formation of water) transfer of electrons

Answer 121

formation of a solid solid formed = precipitate reaction = precipitation reaction

Answer 122

insoluble solid

Answer 123

a substance that completely breaks apart into ions when dissolved in water resulting solution readily conducts an electric current Ba(NO₃)₂ and K₂CrO₄

Answer 124

readily dissolves in water

Answer 125

only a small amount of the solid dissolves in water

Answer 126

all salts when ionic compounds dissolve, the resulting solution contains ions

Answer 127

1. exchange anions & cations 2. balance charges 3. balance equation 4. use solubility rule to find precipitates

Answer 128

two reactants combine to form a single product. the reactants may be elements or compounds Zn(s) + I₂(s) → ZnI₂(s)

Answer 129

one reactant, a compound, breaks down to give 2+ products 2H₂O₂(aq) → 2H₂O(l) + O₂(g)

Answer 130

an element reacts with a compound and replaces one of the elements in the compound metals replace hydrogen or other metals; nonmetals replace nonmetals Zn(s) + 2HCl(aq) → H₂(g) + ZnCl₂(aq)

Answer 131

2 ionic compounds exchange ions to form new compounds NaCl(aq) + AgNO₃(aq) → AgCl(s) + NaNO₃(aq)

Answer 132

a compound burns in the presence of oxygen, producing energy in the form of heat and light the combustion of organic compounds produces carbon dioxide and water C₄H₈(l) + 6O₂(g) → 4CO₂(g) + 4H₂O(g)

Answer 133

shows the overall reaction but not necessarily the actual forms of the reactants & products in solutions balanced in charge & molecules K₂CrO₄(aq) + Ba(NO₃)₂(aq) → BaCrO₄(s) + 2KNO₃(aq)

Answer 134

represents all reactants & products that are strong electrolytes as ions all reactants & products r included 2K+(aq) + CrO₄^2-(aq) + Ba²⁺(aq) + 2NO₃^-(aq) → BaCrO₄(s) + 2K⁺(aq) + 2NO₃^-(aq) when writing ions, put charge on top right, and change subscript to coefficient (unless polyatomic - in which case, MAKE SURE the subscript is EXTRA)

Answer 135

ions that don't participate directly in a reaction

Answer 136

includes only those components that undergo a change spectator ions r not included Ba²⁺(aq) + CrO₄^2-(aq) → BaCrO₄(s) [Ba²⁺ and CrO₄^2- both changed from aq to s]

Answer 137

if 2 elements being combined have the same subscript, u can take it away and change it to a coefficient

Answer 138

most elements occur in nature as a mixture of isotopes average mass of an atom in an element, expressed in atomic mass units (amu) or grams/mole this is one reason why atomic masses r not whole #'s - *they are based on averages* the average atomic weight of an element can be calculated if the abundance of each isotope for that element is known Ex: Chlorine = mixture of 2 isotopes ³⁵Cl - 34.96885268 amu - 75.77% abundance ³⁷Cl - 36.96590259 amu - 24.23% abundance ³⁵Cl → (75.77/100) • 34.97 amu = 26.50 amu ³⁷Cl → (24.23/100) • 36.97 amu = 8.95 amu 26.5amu + 8.95amu = 35.45 amu = average atomic mass for chlorine

Answer 139

atomic mass unit = 1/12th of the mass of a 12C atom = 1/661 x 10-24 gram

Answer 140

number of atoms in 12.000g of ¹²C can be calculated one atom ¹²C = 12.000 amu (by definition) = 12.000amu x (1.661 x 10^-24g/amu) 1 atom = 1.993 x 10^-23g number of atoms = 12.000g • (1 atom/1.993 x 10^-23g) = 6.02 x 10²³ atoms * the # of atoms of any element needed to equal its atomic mass in grams will always be **6.022 x 10²³** atoms, a quantity known as the **mole **(also known as Avogadro's number) * one mole equals the **atomic mass** in grams of an element * mass of 1 mole of ¹²C = 12.000g * mass of 1 mole of C = 12.011g * mass of 1 mole of Na = 22.990g * mass of 1 mole of H = 1.008g * mass of 1 mole of O = 15.999g

Answer 141

total mass for all atoms in a compound

Answer 142

the mass (in grams) of 1 mol of the compound and is the sum of the masses of the component atoms

Answer 143

Calculate the mass, in amu, of a sample of aluminum that contains 75 atoms. 1. 1 Al atom = 26.98 amu 2. 75 Al atoms x (26.98amu/Al atom) = 2024amu

Answer 144

Calculate the # of sodium atoms present in a sample that has a mass of 1172.49 amu 1. 1 Na atom = 22.99 amu 2. 1172.49amu x (1 Na/22.99amu) = 51.00 Na atoms

Answer 145

Compute both the # of moles of atoms and the # of atoms in a 10.0-g sample of aluminum. 1. 1 mol Al = 26.98 g Al 2. 10.0g Al x (1mol Al/26.98g Al) = 0.371 mol Al 3. 6.022 x 10²³ Al atoms = 1 mol Al atoms 4. 0.371 mol Al x (6.022 x 10²³ Al atoms/1 mol Al) = 2.23 x 10²³ Al atoms

Answer 146

How many silicon(Si) atoms are present in 5.68mg? The average atomic mass for Si is 28.09 amu 1. 1g = 1000mg 2. 5.68mg Si x (1g Si/1000mg Si) = 5.68 x 10^-3 g Si 3. 1 mol Si atoms = 28.09 g Si 4. 5.68 x 10^-3 g Si x (1 mol Si/28.09 g Si) = 2.02 x 10^-4 mol Si 5. 1 mol = 6.022 x 10²³ 6. 2.02 x 10^-4 mol Si x (6.022 x 10²³ atoms/1 mol Si) = 1.22 x 10²⁰ Si atoms

Answer 147

proton (H⁺) donor

Answer 148

a proton acceptor

Answer 149

the general reaction that occurs when an acid is dissolved in water can best be rep-ed as an aicid donating a proton to a water molecule to form a new acid (the **conjugate acid**) and a new base (**the conjugate base**) HA(aq)(acid) + H₂O(l)(base) → H₃O⁺(aq)(conj acid) + A^-(aq)(conj base) this model emphasizes the role of the water molecule in pulling the proton from the acid

Answer 150

formed when the proton is transferred to the base

Answer 151

2 substances related to each other by the donating and accepting of a single proton HA(aq)(acid) + H₂O(l)(base) → H₃O⁺(aq)(conj acid) + A^-(aq)(conj base) ↑↑↑there are 2 acid-base pairs: HA(acid) and A^-(base) and H₂O(base) and H₃O⁺(acid)

Answer 152

HCl(aq)(acid) + H₂O(l)(base) → H₃O⁺(aq)(conj acid) + Cl^-(aq)(conj base) * in this case, HCl is the acid that loses an H⁺ ion to form Cl^-, its conjugate base * H₂O (acting as a base) gains an H⁺ ion to form H₃O⁺ (the conj acid) * H₃O⁺ is called the hydronium ion

Answer 153

1. HF, F^-→ yes. lost H⁺ 2. NH₄⁺, NH₃ → yes. lost H⁺ 3. HCl, H₂O → no 1 & 2 are conjugate acid-base pairs cuz the 2 species **differ by one H⁺**

Answer 154

the conj acid & conj base can also react w/ each other to reform the parent molecule and water. a reaction can occur in both directions (other = forward reaction) the products in the forward reaction = the reactants in the reverse reaction we use double arrows to rep reactions that occur in both directions

Answer 155

HA(aq) + H₂0(l) ↔ H₃O⁺(aq) + A^-(aq) this rep's a competition for the H⁺ ion b/w the H₂O in the forward reaction and the A^- in the reverse direction (either H⁺ or A^- will go with H₂O) if the H₂O has a higher attraction for H⁺ compared to A^-, then the solution will contain mostly H₃O⁺ and A^-. The forward reaction dominates and the acid is completely ionized or dissociated. has relatively **weak conjugate base**

Answer 156

if the H₂O has a higher attraction for A^-compared to H⁺ then the solution will contain mostly HA and H₂O. the reverse reaction dominates and most of the acid remains as HA. relatively **strong conj base** Ex: acetic acid. most of the acid remains intact when dissolved in water.

Answer 157

contributes 2 H⁺ ions when dissolved in water Ex: sulfuric acid, H2SO4

Answer 158

can act as an acid or a base H₂O in the ionization of water, a proton transfers from one molecule of water to the other, producing a hydroxide ion and a hyronium ion H₂O(l) + H₂O(l) ↔ H₃O⁺(aq) + OH^-(aq) in this reaction, 1 water molecule acts as an acid by donating a proton. the other acts as a base by accepting a proton the forward reaction doesn't occur to a great extent, meaning that in pure water, very little amounts of hydronium and hydroxide ions exist.

Answer 159

[] used to denote this [H₃O⁺] = [OH^-] = 1.0 x 10^-7 M in water [H₃O⁺] can also be written as [H⁺] (volume of acid)(concentration of acid) = (volume of base)(concentration of base) V_a • M_a = V_b • M_b measured in units of solute/liter of solution -or- molarity

Answer 160

the product of [H⁺] [OH^-] = (1.0 x 10^-7(1.0 x 10^-7) = 1.0 x 10^-4 and is a constant noted as K_w K_w = [H⁺] [OH^-] = 1.0 x 10^-4 \*\* because the product is constant, if [H⁺] increases, [OH^-] must decrease. If [H⁺] decreases, [OH^-] must increase

Answer 161

in a solution, there are 3 possible situations 1. adding an acid to water, increasing [H⁺] [H⁺] \> [OH^-] → **acidic solution** 1. adding a base to water, increasing [OH^-] [H⁺] \< [OH^-] → **basic solution** 1. having equal amounts of acid and base [H⁺] = [OH^-] → **neutral solution**

Answer 162

a convenient way to express the acidity of a solution pH = -log[H⁺] 1-6 = acidic 7 = neutral 8-14 = basic

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