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Flashcards in Flashcards Deck (264):
1

Can molecules with polar bonds be non polar?

Yes if there is no net dipole moment

2

What is the shape of an s orbital?

spherical

3

what is the shape of p orbital?

bi-lobed

4

Which type of bonds form between atoms with small differences in electronegativity (.4-1.7)?

polar covalent bonds

5

Which type of bond forms between atoms with the same electronegativities?

non polar covalent bonds

6

What is a coordinate covalent bond?

one in which a pair of bonding electrons originates from just one of the atoms.

7

(T/F) A dipole moment exist when a molecule has a separation of positive and negative charges.

true

8

What is the formula for calculating formal charge on an atom involved in a covalent bond?

Formal charge= V-(1/2 N bonding + N nonbonding)

9

What are resonance structures?

2 or more non-identical lewis structures for the same molecules

10

(T/F) A lewis structure with small or no formal charges is preferred over one with large formula charges.

true

11

Should a negative formal charge be placed in highly electronegative atoms or weakly electronegative atoms?

highly electronegative atoms.

12

what are the bond orders of single, double, and triple bonds?

single=1st order
double=2nd order
triple=3rd order

13

(T/F) A triple bond is longer than a single bond..

False

14

What is a bond energy?

amount of energy required to separate two bonded atoms

15

Can both bonding and nonbonding electrons be valence electrons?

yes.
nonbonding e- = not involved in a bond
bonding e- = involved in a bond

16

Which type of elements contains the halogens?

group VIIA

17

Which group of elements contains alkaline earths?

group IIA

18

Which group of elements contains noble gases?

group VIIIA

19

Which groups of elements contain the transition metals?

groups IB to VIIIB

20

what is an ionic bond?

transfer of electrons between two atoms

21

what is a covalent bond?

sharing of electrons between two atoms

22

what is a polar covalent bond?

has properties of ionic and covalent bonds. electrons are shared but not equal.

23

what is a cation?

positively-charged ion

24

(T/F) Metals are found on the left side of the periodic table and are good conductors of electricity and heat.

True

25

(T/F) Non metals are found in the middle of the periodic table and are malleable, ductile and shiny.

False

26

(T/F) Metalloids are found between the metals and nonmetals and have varying properties.

True

27

Which group of elements contains the alkali metals?

Group IA

28

What is the electron affinity trend within the periodic table?

increases left to right across a period & up a group.

29

(T/F) Group VIIIA elements have high electron affinities.

False

30

What is electronegativity?

measure of attraction an atom has for the electrons in a chemical bond.

31

What is the electronegative trend within the periodic table?

increases left to right across a period and up a group.

32

What happens to the number of electrons when one moves from left to right across a row?

added as you move across a row.

33

Are electrons more tightly held or less highly held as one moves down a column?

tightly

34

What is the atomic radii trend within the periodic table?

decrease as you move from left to right across a period and up a group.

35

Does a period run horizontally or vertically?

Horizontally

36

Does a group run horizontally or vertically?

Vertically

37

(T/F) Groups have the same valence configuration and have similar chemical properties.

True

38

Which group A or B contains the representative elements?

A

39

(T/F) one amu is equal to 1/12 the mass of a carbon-12 atom.

True

40

how many particles are in a mole?

6.02 x 10 ^23

41

what is atomic weight?

reflects the number of grams per mole of the element. The atomic weight is usually derived from a weighted average of the naturally occurring isotopes of the element.

42

what is an isotope?

different form of the same element due to a different number of neutrons.

43

What are the 3 steps for determining geometric configuration?

1. draw lewis structure
2. count bonding and non bonding electron pairs in the valence shell of the central atom
3. arrange the electron pairs around the central atom so that they are as far apart as possible.

44

what is an anion?

negatively- charged ion.

45

which type of bonds forms between two atoms with substantial differences in electronegativities (>1.7)?

ionic bonds

46

(T/F) all atoms bond according to the "octet rule"

False.

47

what are some characteristics of ionic compounds?

crystal lattices
conduct electricity in solution
high melting
boiling points

48

what is ionization energy?

energy required to completely remove an electron from an atom.

49

compare the values of the first ionization and second ionization energy of an atom.

second ionization higher than first

50

what is electron affinity?

energy released when an atom accepts an electron.

51

How s a photon's energy related to its wavelength?

energy is inversely proportional to wavelength

52

How is a photon's energy related to its frequency?

energy is proportional to frequency

53

What is a paramagnetic material?

unpaired electrons

54

What is a diamagnetic material?

no unpaired electrons

55

How many fourth quantum numbers (ms) are possible for an electron?
What are they?

two.
+1/2 and -1/2

56

What is Hund's rule?

electrons will fill to create the max number of half-filled orbitals.

57

what are the first four subshells?

s,p,d and f

58

what is the formula for the max number of electrons allowed in a subshell?

(4l+2)

59

what does the magnetic (3rd) quantum number (ml) represent?

represent an orbital within a subshell. The possible values range from -l to l

60

How many orbitals can each subshell accommodate?

7

61

What are three types of intermolecular forces?

dipole-dipole interactions
hydrogen bonding
dispersion forces

62

state the intermolecular forces in order of increasing strength.

dispersion forces

63

which molecules, polar or non polar, typically have higher boiling points?

polar molecules typically have higher boiling points.

64

Geometric arrangement:
CO2

Linear

65

Geometric arrangement:
BH3

trigonal planar

66

Geometric arrangement:
NH3

pyramidal

67

Geometric arrangement:
CH4

tetrahedral

68

Geometric arrangement:
PCl5

trigonal bipyramidal

69

Geometric arrangement:
SF6

octahedral

70

How many more protons are in a carbon-14 from than in a carbon-12 atom?

none.

71

what is an atomic emission spectrum?

electrons fall to their ground state

72

what is an atomic absorption spectrum?

electrons are excited to higher energy levels.

73

define Heisenberg uncertainty principle.

it is impossible to know both the momentum and position of an electron at the same time.

74

what are valence electrons?

electrons farthest from the nucleus, as well as many electrons available for bonding.

75

Define the Pauli exclusion principle?

no two electrons in an atom can have the same quantum numbers.

76

what does the principal (1st) quantum number (n) represent?

shell

77

what is the maximum number of electrons allowed in the second shell (n=2)?

2n^2

78

What does the azimuthal (2nd) quantum number (l) represent?

subshell

79

Classify the Rxn:
A+X -> AX

Combination or additon

80

Classify the Rxn:
AX -> A + X

decomposition

81

Classify the Rxn:
AX + B -> BX + A

single displacement

82

Classify the Rxn:
AX+ BY -> AY + BX

double displacement

83

Classify the Rxn:
HA (aq) + BOH (aq) -> AB (aq) + H2O

neutralization

84

What is an empirical formula?

simplest whole number ratio of the element in a compound.

85

What is a molecular formula?

actual number of atoms each element present in a molecule of the compound.

86

what is the formula for calculating % composition

mass of X compound / MW of compound x 100%

87

What is molar mass (molar weight)?

Number of grams per molecule

88

what is the formula for gram equivalent weight?

Molar mass / n = Gram equivalent weight.

89

what is the formula for calculating equivalents?

Weight of compound/ Gram equivalent weight= equivalents

90

How do increasing temp and reactant concentration affect the rate of the reaction?

increases the rate of most reactions.

91

can the medium in which a reaction takes place affect the reaction rate?

yes

92

how does a catalyst increase reaction rate?

by decreasing activation energy

93

what is the reaction rate of the following one step reaction:
2A + B -> A2B

Rate = k [A]^2 [B]

94

what is the enthalpy change of a reaction?

difference between potential energy of the products and the potential energy of the reactants

95

what is the general formula for the rate law of the following reaction?
aA + bB -> cC + dD

rate= k [A]^x [B]^y

96

What is the reaction order for the following rate law?
rate= k [A] [B]^2

Reaction order =3
(x=1, y=2, and order =x+y)

97

Is the rate of a zero order reaction dependent on the concentration of the reactants?

No, a zero order reaction has a constant rate that is independent of the concentration of reactants.

98

what is an elementary reaction?

reaction that can not be decomposed into other reactions

99

(T/F) A complex reaction can be broken down into two or more elementary reactions.

True

100

what is an intermediate?

complex that appears during the course of a reaction but does not appear in the net reaction or as a final product.

101

what is the rate determining step of a reaction?

slowest step of a reaction

102

what is theoretical yield?

amount of product that can be predicted

103

what is actual yield?

amount of product actually isolated from the run experimentally

104

What is percent yield and what is the formula for calculating it?

relationship between actual yield and theoretical yield
actual/theoretical x 100%

105

What is the equilibrium constant expression for the following reaction:
A+ 3B -> 2C + 2D

Keq= [C]^2 [D]^2 / [A] [B]^3

106

Do pure solids or liquids appear in an equilibrium constant expression?

No

107

Does Keq for a reaction remain constant at all temperatures?

No

108

If there is much more product than reactant at equilibrium, what can be said of Keq (as compared to 1)?

Keq>1

109

If Keq is very small compared to 1, then what can be said about the amount of reactants and products at equilibrium?

Keq

110

According to Le Chatelier's principle, in which direction will equilibrium shift if products are removed?

will shift to favor the forward reaction.

111

(T/F) Increasing the pressure of a system will shift equilibrium so as to increase the number of moles produced.

False.
Increasing pressure will shift equation so as to produce fewer molecules of gas.

112

What is an isolated system?

an isolated system can not exchange energy or matter with its surroundings.

113

What is a closed system?

a closed system can exchange energy but can not exchange matter with its surroundings.

114

what is an open system?

an open system can exchange both energy and matter with its surroundings

115

what is an isothermal process?

process that can occur @ constant temp.

116

what is an isobaric process?

process that takes place @ constant pressure.

117

what is an adiabatic process?

process to which no heat exchange occurs between the system and the surroundings

118

(T/F) heat absorbed by a system is considered positive and heat lost by a system is considered negative.

true

119

what is an endothermic process?

process that absorbs heat from the surroundings.

120

what is an exothermic process?

release heat

121

what is the formula for calculating heat (q) absorbed or released by a process.

q= (mass)(heat capacity)(change in temp)= mcAt

122

what is the formula for calculating Delta Hrxn?

(sum of Delta Hf of products)-( Sum of Delta Hf of reactants)

123

Does a positive Delta H correspond to an endothermic or exothermic process

endothermic process.

124

Does a negative Delta H correspond to an endothermic or exothermic process?

exothermic

125

What is standard heat of formation ( Deta Hf)?

enthalpy change that occurs when one mole of a compound is formed from its elements in their standard states.

126

What is the Delta Hf of an element in its standard state?

0

127

(T/F) Hess's law states that enthalpies of reactions are additive.

True

128

If the Delta H of a forward reaction is -220kJ, what is the Delta H of the reverse reaction?

+220kJ

129

What is bond dissociation energy?

amount of energy required to break a particular bond in one mole of gaseous molecules.

130

What is entropy?

measure of disorder or randomness of a system.

131

When does a system reach max entropy?

@ equilibrium

132

What is the Gibb's free energy equation? ΔG=

ΔG= ΔH- T ΔS

133

How does the value of ΔG correlate with the spontaneity of a reaction?

Δ G is negative for spontaneous rxn.
Δ G is positive for non-spontaneous run

134

What is the value of ΔG for a system @ eq?

0

135

(T/F) A reaction with (+) ΔH and (-) ΔS is always spontaneous.

False

136

Under what conditions will a run with (+) ΔH and (+) ΔS be spontaneous?

@ high temp

137

under what conditions will a reaction with (-)ΔH and (-) ΔS be spontaneous?

@ low temp

138

what is standard free energy, ΔG?

process occurring @ 25 C, 1 atm of pressure and when the concentrations of all reactant and products are 1M

139

what is standard free energy formation ΔGf?

free energy change that occurs when 1 mol of a compound in its standard state is formed from its elements in their standard states.

140

what is the formula relating ΔG to Keq?

ΔG= -RT ln Keq

141

(T/F) Once a reaction commences:
ΔG= ΔG+ RTln Q

True

142

What are the three phases of matter?

solid
liquid
gas

143

What is standard pressure in atm, mm Hg and torr?

1atm=760 mmHg= 760 torr

144

What is standard term in Kelvin? celsius?

273 K
0C

145

(T/F) an ideal gas represents a hypothetical gas whose articles take up no volume and experience no intermolecular forces.

True

146

What is Boyle's law?

under isothermal conditions, pressure is inversely proportional to volume.
P1V1=P2V2

147

What is Charles Law?

under constant pressure, volume is directly proportional to absolute temp.
(V1/T1)=(V2/T2)

148

(T/F) Avogadro's principle states that at constant temp and pressure, volume is directly proportional to the number of moles of gas.

True

149

what is the ideal gas law?

PV=nRT

150

what is the difference between I.P and Ksp?

I.P is defined with respect to initial concentrations.
Ksp is defined with respect to the concentrations of a saturated solution at equilibrium.

151

(T/F) Metals, which are on the left side of the periodic table, generally form positively-charged ions. non-metals on the right side generally from negative-charged ions.

True

152

What is an electrolyte?

solute whose solution is conductive

153

What is the formula for percent composition by mass?

mass of solute/ mass of solution x 100%

154

What is the definition of mole fraction (X)?

moles of compound/ total number of moles.

155

What is the definition of molarity?

moles of solute/ L in solution

156

what is the definition of molality?

moles of solute/ Kg of solvent

157

what is the definition of normality?

GEW of solute/ L of solute.

158

(T/F) A solution which is diluted is related to its initial concentration as follows: M1V1= M2V2

True

159

Name:
Cu+

Copper (I)
or
Cuprous

160

Name:
Cu+2

Copper (II)
or
Cupric

161

Name:
H-

Hydride

162

Name:
ClO-

Hypochlorite

163

Name:
ClO2-

Chlorite

164

Name:
ClO3-

Chlorate

165

Name:
ClO4-

Perchlorate

166

What is the Arrhenius definition of an acid?
Of base?

Arrhenius acid: produces H+ in aq solution.
Arrhenius base: produces OH- in aq solution.

167

What is the Bronsted-Lowry definition of an acid?

donates protons

168

What is the Bronsted-Lowry definition of an base?

accepts protons

169

If the I.P is larger than the solubility product constant (Ksp), is the solution saturated. unsaturated or supersaturated?

I.P> Ksp supersaturated

170

If the I.P is smaller than the solubility product constant (Ksp), is the solution saturated. unsaturated or supersaturated?

I.P

171

If the I.P is equal than the solubility product constant (Ksp), is the solution saturated. unsaturated or supersaturated?

I.p = Ksp saturated

172

what is the common ion effect?

when a slightly soluble salt is added to a solution which already contains one of its components, the added salt is less soluble than if it were added to a pure solvent.

173

what is the name of the process for combing smaller nuclei into larger nuclei?

Fusion is the combining of smaller nuclei to create a larger nuclei.

174

what is nuclear fission?

splitting of atomic nuclei

175

Define reduction potential

tendency of species to acquire electrons.

176

Whats the formula for EMF

EMF= E red+ E ox

177

(T/F) When adding standard potentials, multiply by the number of moles oxidized or reduced first.

False

178

what is the formula for the standard free energy of an electrochemical cell?

ΔG= -(number of moles) (Faraday's constant)(EMF)
= -nFE

179

what is the relationship between EMF and Keq?

nFE= RT ln Keq

180

If the half life of an isotope is 2 years, how much of the original isotope will be left after 4 years?

25%

181

What is the formula for exponential decay?

n=no e ^ -λt

182

what is mass defect?

difference between the mass of a nucleus and the sum total of its constituents (nucleons)

183

what formula is used for calculating binding energy?

Energy= (mass defect)(speed of light)^2
Δmc^2

184

What is the oxidation number of free elements?

0

185

(T/F) Group IA elements usually have a +1 charge in a compound, and group IIA usually have a +2

true

186

what is the oxidation number of oxygen in most compounds?

-2

187

What is the oxidation number of Group VIIA element in a compound?

-1
except: if a group VIIA element is combined with and element with higher electronegativity, then the oxidation number is +1 or higher

188

what are the two types of electrochemical cells?

galvanic (voltanic)
electrolytic

189

does oxidation occur at the anode or cathode?

anode

190

does reduction occur at the anode or cathode?

cathode

191

which type of electrochemical cell generates energy?

galvanic

192

Does a galvanic cell have a positive or negative ΔG?

negative= spontaneous

193

what is the function of a salt bridge?

permits balancing of charge between cells

194

(T/F) A cell diagram adheres to the following conventions:
anode/anode solution// cathode solution/cathode

true

195

does an electrolytic cell have positive or negative ΔG?

positive= non- spontaneous

196

In which electrochemical cell is the anode positive?

electrolytic cell

197

In which electrochemical cell is the cathode positive?

galvanic cell

198

what is faraday (F)?

F is equivalent to the amount of charge contained in one mole of electrons = 96,487 C.

199

(T/F) Electrons always flow from the anode to the cathode.

True

200

(T/F) An acid equivalent is equal to one mole of H+

True

201

Does high Ka correspond to weak or strong acid?

High Ka= strong acid

202

Does high Kb correspond to weak or strong acid?

High Kb= weak acid.

203

What is a polyprotic acid?

can lose more than one proton
ie: H2SO4 or H3PO4

204

what is an amphoteric species?

can act as acid or base

205

ph?
Strong acid + Strong base

pH of 7

206

pH?
Weak acid + Strong base

pH greater than 7

207

(T/F) A buffer solution consist of a mixture of a strong acid and its salt

False.
buffer= mix of weak acid & its salt

208

What is the henderson-Hasselbalch equation for a weak acid buffer solution?

pH= pKa + Log (conjugate base)/(weak acid)

209

What is the Henderson-Hasselbalch equation for a weak base buffer solution?

pOH=pKb + log (conjugate acid)/(weak base)

210

Does the gain of electrons result in reduction or oxidation?

reduction

211

Does the loss of electrons result in reduction or oxidation?

oxidation

212

(T/F) An oxidizing agent is oxidized in an electrochemical reaction.

False

213

what is a reducing agent?

species that loses electrons and thereby causes another agent to be reduced.

214

What is the lewis definition of an acid?

accepts electron pair

215

What is the lewis definition of an base?

donates electron pair

216

(T/F) All broasted-lowry acids are lewis acids.

true

217

Name:
HF

Hydrofluoric acid

218

Name:
HClO4

Perchloric acid

219

Name:
HNO2

Nitrous acid

220

Name:
HNO3

Nitric acid

221

what is the water dissociation constant @ 25 C? Kw=

Kw=[H+][OH-]=10^-14

222

What is the pH of a solution @ 25C with a pOH of 5?

pH= 14-pOH =9

223

What is the log formula for calculating pH?

pH= -log [H+]

224

What is the log formula for calculating pOH?

pOH= -log [OH-]

225

What is the pH of a 1 x 10^-14 M HCl solution?

pH=4

226

would the pH of a 1.4 x 10^-14 M HCl solution be greater or less than 4?

less than 4

227

What is the product of a neutralization reaction?

salt

228

will the titration of a weak acid with a strong base produce a slightly acidic or slightly basic solution?

basic

229

will the titration of a strong acid with a strong base produce a slightly acidic or slightly basic or neutral solution?

neutral

230

will the titration of a strong acid with a weak base produce a slightly acidic or slightly basic solution?

acidic

231

(T/F) Solids and liquids are often referred to as the condensed phases.

True

232

What does it mean when two liquids are immiscible?

liquids repel each other and do not mix to form a solution.

233

What is an emulsion?

mix of immiscible liquids which are broken up into extremely small particles.

234

What is an amorphous solid?

no ordered 3D arrangement.

235

What are the two most common types of crystalline solids?

ionic & metallic

236

(T/F) A unit cell is a repeating unit of crystals

True

237

What is condensation?
Evaporation?

Condensation: gas to liquid
Evaporation: liquid to gas

238

What is fusion?

solid to liquid

239

what is solidification (crystallization)?

liquid to solid

240

What is sublimation?

solid to gas

241

what is deposition?

gas to solid

242

(T/F) The rates at which two gases diffuse are inversely proportional to the square root of their molar masses.

true

243

what is effusion?

flow of gas particles under pressure from one container to another through a small opening.

244

(T/F) The rates of effusion for 2 molecules are directly proportional to the square root of their molar masses.

False.

245

What is Dalton Law of Partial pressure?

the total pressure of a gaseous mix is equal to the sum pf partial pressure of the individual components.

246

What is the formula for calculating partial pressure?

PA= Pt XA ; XA= mol of A/ total mol

247

(T/F) A gas molecule's kinetic energy is inversely proportional to the absolute temp of the gas

False.
Kinetic energy is directly proportional to the absolute temp.

248

Under what conditions is the ideal gas law most correct?

gases behave in a near-ideal fashion at low temp and high temp.

249

How do actual volume and predicted volume of a gas compare at moderately high pressures? Extremely high pressures?

Moderately high: gas volume less than would be predicted
Extremely high: gas volume more than would be predicted

250

How do actual volume and ideal volume of a gas compare at very low temp?

low temp: actual volume less than would be predicted.

251

What is the volume of 1 mole of gas at STP?

22.4 L

252

What are the typical units of density for a gas?

g/L

253

(T/F) For a specific sample of gas, (P1VA/T1)=(P2V2/T2)

True

254

What is the formula for calculating the density of a gas?

d=m/V= P(MM)/RT

255

What is an aqueous solution?

one which water is the solvent

256

what is solubility?

measure of the amount of substance that can be dissolved in a particular solvent @ a particular temp

257

what is a saturated solution?

contains mx amount of solute that can be dissolved in a particular solvent @ a particular temp

258

Is osmotic pressure proportional to molarity?

yes

259

What is the formula for osmotic pressure?

π= MRT

260

What is the formula for the vapor pressure of A in a solution of A and B?

PA= XA PA

261

What is a colligative property?

property derived sole from the number of particles present, not the nature of those particles.

262

Name the 4 colligative properties.

freezing point depression
boiling point elevation
osmotic pressure
vapor pressure lowering

263

What is the formula for freezing-point depression?

ΔTf=Kf m

264

What is the formula for boiling-point elevation?

ΔTb= Kb m