chemistry westcott 8-21

Calculate the heat capacity, in joules per degree, of the following: 28.4 g of water 529 J//°C 19 J//°C 52 J//°C 119 J//°C

119 J//°C

What is the half-life for the first-order decay of phosphorus-32? (3215P⟶3216S+e−)(1532P⟶1632S+e−) The rate constant for the decay is 4.85 ×× 10−2 day−1. 10.3 d 28.8 d 14.3 d 4.4 d

14.3 d

What mass of carbon monoxide must be burned to produce 175 kJ of heat under standard state conditions? 17.3 g .173 g 34.6 g 100 g

17.3

Doubling the concentration of a reactant increases the rate of a reaction four times. With this knowledge, answer the following questions: (a) What is the order of the reaction with respect to that reactant?(b) Tripling the concentration of a different reactant increases the rate of a reaction three times. What is the order of the reaction with respect to that reactant?

2,1

Tripling the concentration of a reactant increases the rate of a reaction nine-fold. With this knowledge, answer the following questions: (a) What is the order of the reaction with respect to that reactant?(b) Increasing the concentration of a reactant by a factor of four increases the rate of a reaction four-fold. What is the order of the reaction with respect to that reactant?

2,1

How much heat is produced by combustion of 125 g of methanol under standard state conditions? 2.8 kJ 4666 kJ 2833 kJ 3.3 kJ

2833 kJ

Determine the cell reaction and standard cell potential at 25 °C for a cell made from an anode half-cell containing a cadmium electrode in 1 M cadmium nitrate and an anode half-cell consisting of an aluminum electrode in 1 M aluminum nitrate solution. Is the reaction spontaneous at standard conditions?

3Cd(s)+2Al3+(aq)⟶3Cd2+(aq)+2Al(s); −1.259 V; nonspontaneous

A 20.0-L cylinder containing 11.34 kg of butane, C4H10, was opened to the atmosphere. Calculate the mass of the gas remaining in the cylinder if it were opened and the gas escaped until the pressure in the cylinder was equal to the atmospheric pressure, 0.983 atm, and a temperature of 27 °C. 5.2 g 101.5 g 92.8 g 46.4 g

46.4 g

How much heat, in joules, must be added to a 75.0g iron block with a specific heat of 0.449 J/g °C to increase its temperature from 25 °C to its melting temperature of 1535 °C? 10.16 × 104 J 5.08 × 104 J 33.68 × 104 J 11.26 × 104 J

5.08 × 104 J

When two cotton plugs, one moistened with ammonia and the other with hydrochloric acid, are simultaneously inserted into opposite ends of a glass tube that is 87.0 cm long, a white ring of NH4Cl forms where gaseous NH3 and gaseous HCl first come into contact. (Hint: Calculate the rates of diffusion for both NH3 and HCl, and find out how much faster NH3 diffuses than HCl.)At approximately what distance from the ammoniamoistened plug does this occur? 26.3 cm 100.7 cm 141.7 cm 51.7 cm

51.7 cm

The pressure of a sample of gas is measured at sea level with an open-end mercury manometer. Assuming atmospheric pressure is 760.0 mm Hg, determine the pressure of the gas in:mm Hg (13.7) 623 mm Hg 62 mm Hg 320 mm Hg 626 mm Hg

623

Assuming ideal solution behavior, what is the boiling point of a solution of 9.04 g of I2 in 75.5 g of benzene, assuming the I2 is nonvolatile? 81.3 °C 66.4 °C 41.3 °C 162.6 °C

81.3 °C

A 45-g aluminum spoon (specific heat 0.88 J/g °C) at 24 °C is placed in 180 mL (180 g) of coffee at 85 °C and the temperature of the two become equal. What is the final temperature when the two become equal? Assume that coffee has the same specific heat as water. 82 °C 164 °C 64 °C 62 °C

82 °C

Calculate the number of moles in 583g of H2SO4 in 1.50 kg of water (the acid solution used in an automobile battery)? 89.24 mol 45.22 mol 188.48 mol 90.30 mol

89.24 mol

The density of liquid NH3 is 0.64 g/mL; the density of gaseous NH3 at STP is 0.0007 g/mL. Which of the following is not an explanation of the difference between the densities of these two phases (more than one answer might apply)? A given volume of a gas contains a much larger number of molecules and a much larger mass than the same volume of a liquid. A given volume of a gas contains a much smaller number of molecules and a much smaller mass than the same volume of a liquid. All of these are true. Molecules of gases are widely separated, whereas molecules in a liquid touch.

A given volume of a gas contains a much smaller number of molecules and a much smaller mass than the same volume of a liquid.

The masses of three electrodes (A, B, and C), each from three different galvanic cells, were measured before and after the cells were allowed to pass current for a while. The mass of electrode A increased, that of electrode B was unchanged, and that of electrode C decreased. Identify each electrode as active or inert. A is inert, B is inert, C is active A is active, B is inert, C is active A, B & C are all active A, B & C are all inert A is inert, B is active, C is inert

A is active, B is inert, C is active

What is the conjugate acid of each of the following? What is the conjugate base of each? (a) OH−(b) HS− (a) H2O, O2−; (b) H2S; S2− (a) H3O2+, HO2−; (b) H2CO3, CO32− (a) H20, O2-; (b) H2CO3, CO32− (a) H2CO3, CO32−; (b) H2S; S2−

(a) H2O, O2−; (b) H2S; S2−

When 1.0 g of fructose, C6H12O6(s), a sugar commonly found in fruits, is burned in oxygen in a bomb calorimeter, the temperature of the calorimeter increases by 1.58 °C. If the heat capacity of the calorimeter and its contents is 9.90 kJ/°C, what is q for this combustion? 30.2 kJ -15.6 -30.2 15.6

-15.6

Dissolving 3.0 g of CaCl2(s) in 150.0 g of water in a calorimeter at 22.4 °C causes the temperature to rise to 25.8 °C. What is the approximate amount of heat involved in the dissolution, assuming the heat capacity of the resulting solution is 4.18 J/g °C? -4.4 kJ -2.2 kJ 2.2 kJ 2 kJ

-2.2 kJ

A 0.500g sample of KCl is added to 50.0 g of water in a calorimeter. If the temperature decreases by 1.05 °C, what is the approximate amount of heat involved in the dissolution of the KCl, assuming the heat capacity of the resulting solution is 4.18 J/g °C? 222 J 44 J -222 J -22 J

-222 J

What is the boiling point of Neon? -180.8 °C -245.9 °C -45.7 °C -22.9 °C

-245.9 °C

The Henry's law constant for O2 is 1.3 10-3 M/atm at 25 °C. Assuming ideal solution behavior, what mass of oxygen would be dissolved in a 40-L aquarium at 25 °C, assuming an atmospheric pressure of 1.00 atm, and that the partial pressure of O2 is 0.21 atm? 0.68 g 0.346 g 0.661 g 0.3 g

0.346 g

A piece of unknown substance weighs 44.7 g and requires 2110 J to increase its temperature from 23.2 °C to 89.6 °C. What is the specific heat of the substance? .094 J/g °C 1.44 J/g °C .103 J/g °C 0.711 J/g °C

0.711 J/g °C

Why is it necessary to use a nonvolatile liquid in a barometer or manometer? A volatile liquid evaporates easily, which would produce some gas pressure in enclosed volumes, thus affecting the measurements. A non-volatile liquid can become a solid, similar to ice freezing. A non-volatile liquid evaporates easily, which would produce some gas pressure in enclosed volumes, thus affecting the measurements. A volatile liquid does not evaporate easily, which would produce 0 gas pressure in enclosed volumes.

A volatile liquid evaporates easily, which would produce some gas pressure in enclosed volumes, thus affecting the measurements.

An active (metal) electrode was found to gain mass as the oxidation-reduction reaction was allowed to proceed. Was the electrode an anode or a cathode?

Active electrodes participate in the oxidation-reduction reaction. Since metals form cations, the electrode would gain mass if metal ions in solution were reduced to metal atoms and deposited on the electrode. Reduction occurs at the cathode.

Why do batteries go dead but fuel cells do not? All of these are reasons batteries go dead but fuel cells do not. Battery reaction byproducts accumulate and interfere with the reaction. Because a fuel cell is constantly resupplied with reactants and products are expelled, it can continue to function as long as reagents are supplied. None of these are reasons batteries go dead but fuel cells do not. Batteries are self-contained and have a limited supply of reagents to expend before going dead.

All of these are reasons batteries go dead but fuel cells do not.

By calculating ΔSuniv at each temperature, determine if the melting of 1 mole of NaCl(s) is spontaneous at 500 °C and at 700 °C. What assumptions are made about the thermodynamic information (entropy and enthalpy values) used to solve this problem?

As ΔSuniv < 0 at each of these temperatures, melting is not spontaneous at either of them. The given values for entropy and enthalpy are for NaCl at 298 K. It is assumed that these do not change significantly at the higher temperatures used in the problem.

How does the boiling of a liquid differ from its evaporation? At the boiling point, the vapor pressure of the liquid is the same as the atmospheric pressure. Evaporation is the term used to describe a relatively high vaporization process that can occur at temperatures below the boiling point. During evaporation, the vapor pressure of the liquid is more than atmospheric pressure.

At the boiling point, the vapor pressure of the liquid is the same as the atmospheric pressure.

Is the self ionization of water endothermic or exothermic? The ionization constant for water (Kw) is 2.9 × 10-14 at 40 °C and 9.3 × 10-14 at 60 °C. Because Kw increases with increasing temperature, the reaction in exothermic. Because Kw decreases with increasing temperature, the reaction in endothermic. Because Kw increases with increasing temperature, the reaction in endothermic. Because Kw decreases with increasing temperature, the reaction in sxoothermic.

Because Kw increases with increasing temperature, the reaction in endothermic.

Write the chemical formula & condensed formula for the following hydrocarbon 3,4-dimethyl-1-pentyne. CH3CCCH2CH2CH2CH3; C16H8 CH3CCCH2CH2CH2CH3; C7H14 CH3CCCH2CH2CH2CH3; C7H12 CH3CCCH2CH2CH2CH3; C6H14

CH3CCCH2CH2CH2CH3; C7H12

Write the chemical formula & condensed formula for the following hydrocarbon heptane. CH3CH2CH2CH2CH2CH2CH2; C6H16 CH3CH2CH2CH2CH2CH2CH3; C6H16 CH3CH2CH2CH2CH2CH2CH3; C7H18 CH3CH2CH2CH2CH2CH2CH3; C7H16

CH3CH2CH2CH2CH2CH2CH3; C7H16

Write the condensed structures of both isomers with the formula C2H6O. CH3OCH3, CH2CH3OH CH2OCH3, CH3CH2OH CH3OCH3, CH3CH2OH CH3OCH2, CH3CH2OH

CH3OCH3, CH3CH2OH

Which of the following slightly soluble compounds has a solubility greater than that calculated from its solubility product because of hydrolysis of the anion present: CoSO3, CuI, PbCO3, PbCl2, KClO4? CoSO3, PbCO3 CoSO3, CuI CoSO3, PbCO3, PbCl2 CuI, PbCO3

CoSO3, PbCO3

A typical barometric pressure in Kansas City is 740 torr. What is this pressure in atmospheres, in millimeters of mercury, and in kilopascals? 5.5 kPa 50.6 kPa 201.3 kPa 101.3 kPa

Correct! 101.3 kPa

A solution of acetic acid and sodium acetate (CH3COOH + CH3COONa) is an example of a buffer that consists of a weak acid and its salt. Correct! TrueA solution of acetic acid and sodium acetate (CH3COOH + CH3COONa) is an example of a buffer that consists of a weak acid and its salt.

Correct! True

Why do the compounds hexane, hexanol, and hexene have such similar names? Each contains a chain of four carbon atoms. Each contains a chain of two carbon atoms. Each contains a chain of one carbon atoms. Each contains a chain of six carbon atoms.

Each contains a chain of six carbon atoms.

Consider the following metals: Ag, Au, Mg, Ni, and Zn. Which of these metals could be used as a sacrificial anode in the cathodic protection of an underground steel storage tank? Steel is an alloy composed mostly of iron, so use -0.447 V as the standard reduction potential for steel

For cathodic protection, the overall reaction must be spontaneous. Thus, the standard cell potential of the anode must be less than the standard reduction potential of steel/iron (the metal to be protected), which, from the problem, has. With standard reductions in parentheses: Mg (-1.185 V), and Zn (-0.7618 V) could be used as a sacrificial anode, while Ag (+0.7996 V), Au (+1.629 V), and Ni (-0.257 V) could not.

Identify and label the Brønsted-Lowry acid, its conjugate base, the Brønsted-Lowry base, and its conjugate acid in each of the following equations: HS−+H2O⟶H2S+OH− HBr(BA), H2O(BB), (CA), Br -(CB) HS-(BB), H2O(BA), H2S(CA), OH-(CB) - H2O(BB), HS-(BA), H2S(CA), OH-(CB) -

HS-(BB), H2O(BA), H2S(CA), OH-(CB) -

Most solid ionic compounds are electrically nonconductive, whereas aqueous solutions of ionic compounds are good conductors. Therefore, would you expect a liquid (molten) ionic compound to be electrically conductive or nonconductive?

I would expect it to be electrically conductive beause a medium must contain freely mobile, charged entities to be electrically conductive.

Is it important that charge balance in oxidation-reduction reactions?

If the charge does not balance, then there would be a different number of electrons on each side of the equation. This would violate the law of conservation of charge.

What is the difference between the hybridization of carbon atoms' valence orbitals in saturated and unsaturated hydrocarbons (mark all that are true)?

In saturated hydrocarbons, the hybridization on atoms is sp3 In unsaturated hydrocarbons, some of the hybridization on atoms is sp2 or sp hybrid

The initial concentrations or pressures of reactants and products are given for the following system. Calculate the reaction quotient and determine the direction in which this system will proceed to reach equilibrium. [NH3] = 0.20 M, [N2] = 1.00 M, [H2] = 1.00 M Kp, proceeds right Kp, proceeds left Kc, proceeds left Kc, proceeds right

Kc, proceeds left

Assuming that no equilibria other than dissolution are involved, calculate the molar solubility of the following from its solubility product: Ag2SO4 Ksp = [Ag+]2 = 1.2 10-5 = (2x)2(x) = 4x4, x = 1.44 10-2M; Ksp = [Ag+]2 = 1.2 10-5 = (2x)2(x) = 4x3, x = 1.44 10-3M; Ksp = [Ag+]2 = 1.2 10-5 = (2x)2(x) = 4x4, x = 1.44 10-4M; Ksp = [Ag+]2 = 1.2 10-5 = (2x)2(x) = 4x3, x = 1.44 10-2M

Ksp = [Ag+]2 = 1.2 10-5 = (2x)2(x) = 4x3, x = 1.44 10-2M

What is the term that defines any species that can accept a pair of electrons and form a coordinate covalent bond? Coupled equilibria Lewis acid Lewis base Ligand

Lewis acid

Is an equilibrium among CH4, O2, CO2, and H2O established under these conditions? Explain your answer.

No, it is not at equilibrium. Because the system is not confined, products continuously escape from the region of the flame; reactants are also added continuously from the burner and surrounding atmosphere.

Is a system at equilibrium if the rate constants of the forward and reverse reactions are equal? Yes, the rate constants having the same value does mean that the rates of the reactions are equal, which defines a system being at equilibrium. No, the rate constants having the same value does not mean that the rates of the reactions are equal, which defines a system being at equilibrium. There is not enough information here to determine

No, the rate constants having the same value does not mean that the rates of the reactions are equal, which defines a system being at equilibrium.

Use solubility products and predict which of the following salts is the most soluble, in terms of moles per liter, in pure water: CaF2, Hg2Cl2, PbI2, or Sn(OH)2. Since each of the compounds dissociates into three ions upon dissolution, their solubilities may be compared by examining the value of the compounds' respective solubility products. The larger the value of Ksp, the greater will be the solubility. The Ksp values are as follows: CaF2: Ksp = 4.0 10-11 Hg2Cl2: Ksp = 1.1 10-18 PbI2: Ksp = 1.4 10-8 Sn(OH)2: Ksp = 3 10-27 CaF2 Sn(OH)2 PbI2 Hg2Cl2

PbI2

______________ energy of the car battery is converted into ______________ energy of the engine starter when the ignition switch is turned or pressed; ___________ energy in the gasoline is converted into heat and mechanical energy through its combustion in the auto's engine.

Potential, kinetic, potential

The initial concentrations or pressures of reactants and products are given for the following system. Calculate the reaction quotient and determine the direction in which this system will proceed to reach equilibrium. [NH3] = 0.50 M, [N2] = 0.15 M, [H2] = 0.12 M Qc < Kc, proceeds left Qc < Kc, proceeds right Qc > Kc, proceeds left QP < KP, proceeds right

Qc < Kc, proceeds right

Determine whether aqueous solutions of the following salt is acidic, basic, or neutral: RbI RbI dissociates into Rb+ ions (neutral metal cation) and I- ions (the conjugate base of a strong acid and therefore essentially neutral). The aqueous solution is therefore acidic. RbI dissociates into Rb+ ions (neutral metal anion) and I- ions (the conjugate base of a weak acid and therefore essentially neutral). The aqueous solution is therefore basic. RbI dissociates into Rb+ ions (neutral metal cation) and I- ions (the conjugate base of a strong acid and therefore essentially neutral). The aqueous solution is therefore neutral.

RbI dissociates into Rb+ ions (neutral metal cation) and I- ions (the conjugate base of a strong acid and therefore essentially neutral). The aqueous solution is therefore neutral.

How will an increase in temperature affect the following equilibria? 2NH3(g)⇌N2(g)+3H2(g)ΔH=92kJ T increase = shift right T increase = no shift T increase = shift left

T increase = shift right

How do the concentrations of Pb2+ and S2- change when K2S is added to a saturated solution of PbS? The added K2S causes the concentration of S2- to increase and the concentration of Pb2+ to decrease via formation of more PbS by the common ion effect. The added K2S causes the concentration of S2- to decrease and the concentration of Pb2+ to increase via formation of more PbS by the common ion effect. The added K2S causes the concentration of S2- to decrease and the concentration of Pb2+ to decrease via formation of more PbS by the common ion effect. The added K2S causes the concentration of S2- to increase and the concentration of Pb2+ to increase via formation of more PbS by the common ion effect.

The added K2S causes the concentration of S2- to increase and the concentration of Pb2+ to decrease via formation of more PbS by the common ion effect.

Describe what happens to the average kinetic energy of ideal gas molecules when the conditions are changed as follows:The pressure of the gas is increased by reducing the volume at constant temperature. The average kinetic energy decreases at a constant temperature The average kinetic energy remains the same at constant temperature The average kinetic energy increases at a constant temperature None of these

The average kinetic energy remains the same at constant temperature

Consider two processes: sublimation of I2(s) and melting of I2(s) (Note: the latter process can occur at the same temperature but somewhat higher pressure).I2(s) → I2(g)I2(s) → I2(l) Is ΔS positive or negative in the processes? In which of the processes will the magnitude of the entropy change be greater? The change of entropy will be positive in the first case, negative in the second case The change of entropy will be negative in the both cases The change of entropy will be positive in the both cases The change of entropy will be negative in the first case, positive in the second case

The change of entropy will be positive in the both cases

Silane (SiH4), phosphine (PH3), and hydrogen sulfide (H2S) melt at -185 °C, -133 °C, and -85 °C, respectively. What does this suggest about the polar character and intermolecular attractions of the three compounds (more than one answer might apply)? The molecules become less polar. The intermolecular forces increase as the melting temperatures increase from -185 °C to -85 °C. The intermolecular forces decrease as the melting temperatures increase from -185 °C to -85 °C. The molecules become more polar.

The intermolecular forces increase as the melting temperatures increase from -185 °C to -85 °C. The molecules become more polar.

Which statement is false?

The lower the surface tension, the stronger the intermolecular forces are.

Why do some small bridges have weight limits that depend on how many wheels or axles the crossing vehicle has (mark all that apply): The more axles/wheels a vehicle has, the more surface area it has that is in contact with the road. For a given weight of vehicle (force applied to the road), a higher area corresponds to a higher pressure. ccc The more axles/wheels a vehicle has, the less surface area it has that is in contact with the road

The more axles/wheels a vehicle has, the more surface area it has that is in contact with the road. For a given weight of vehicle (force applied to the road), a higher area corresponds to a lower pressure.

If the temperature of a fixed amount of a gas is doubled at constant volume, what happens to the pressure? The pressure is doubled. The pressure is quadrupled. The pressure stays the same. The pressure is halved.

The pressure is doubled.

A helium-filled balloon spontaneously deflates overnight as He atoms diffuse through the wall of the balloon. Describe the redistribution of matter and/or energy that accompanies this process. The process involves a greater dispersal of matter as the He atoms transfer from a relatively large initial volume (the balloon) to a much smaller final volume (the room, or house, or ultimately earth's atmosphere). The process involves a reduced dispersal of matter as the He atoms transfer from a relatively small initial volume (the balloon) to a much larger final volume (the room, or house, or ultimately earth's atmosphere). The process involves a greater dispersal of matter as the He atoms transfer from a relatively small initial volume (the balloon) to a much larger final volume (the room, or house, or ultimately earth's atmosphere).

The process involves a greater dispersal of matter as the He atoms transfer from a relatively small initial volume (the balloon) to a much larger final volume (the room, or house, or ultimately earth's atmosphere).

How will increasing the concentration of CO from 0.02 M to 0.06 M affect the rate of the reaction? The rate increases by a factor of 3. The rate decreases by a factor of 3. The rate idecreases by a factor of 32 The rate increases by a factor of 2

The rate increases by a factor of 3.

How will increasing the pressure of NO2 from 0.1 atm to 0.3 atm affect the rate of the reaction? The rate decreases by a factor of 3. The rate increases by a factor of 36 The rate increases by a factor of 3. The rate decreases by a factor of 2

The rate increases by a factor of 3.

Explain why the neutralization reaction of a strong acid and a weak base gives a weakly acidic solution. The reaction forms the conjugate acid of the strong base. The reaction forms the conjugate acid of the weak base. The salt ionizes in solution, but the ion slightly reacts with water to form the weak acid. The conjugate acid of a weak base is a weak acid and ionizes to a slight extent giving an acidic solution.

The reaction forms the conjugate acid of the weak base. The conjugate acid of a weak base is a weak acid and ionizes to a slight extent giving an acidic solution

Explain what happens as a reaction starts with ΔG < 0 (negative) and reaches the point where ΔG = 0. The reaction starts with Q < K as the reaction proceeds, and Q increases until equilibrium is reached (where Q = K). The reaction starts with Q > K as the reaction proceeds, and Q decreases until equilibrium is reached (where Q = K). The reaction starts with Q < K as the reaction proceeds, and Q decreases until equilibrium is reached (where Q = K). The reaction starts with Q > K as the reaction proceeds, and Q increases until equilibrium is reached (where Q = K).

The reaction starts with Q < K as the reaction proceeds, and Q increases until equilibrium is reached (where Q = K).

A large scuba tank with a volume of 18 L is rated for a pressure of 220 bar. The tank is filled at 20 °C and contains enough air to supply 1860 L of air to a diver at a pressure of 2.37 atm (a depth of 45 feet). Was the tank filled to capacity at 20 °C? The tank was empty The tank was filled to capacity The tank was not filled to capacity The tank was overfilled

The tank was overfilled

The molecular mass of butanol, C4H9OH, is 74.14; that of ethylene glycol, CH2(OH)CH2OH, is 62.08, yet their boiling points are 117.2 °C and 174 °C, respectively. What is the best explanation for the difference? The two hydroxyl groups in ethylene glycol provide less locations for the formation of hydrogen bonds. The existence of more hydrogen bonds considerably increases the boiling point. The two hydroxyl groups in ethylene glycol provide more locations for the formation of hydrogen bonds. The existence of more hydrogen bonds considerably decreases the boiling point. The two hydroxyl groups in ethylene glycol provide less locations for the formation of hydrogen bonds. The existence of more hydrogen bonds considerably decreases the boiling point. The two hydroxyl groups in ethylene glycol provide more locations for the formation of hydrogen bonds. The existence of more hydrogen bonds considerably increases the boi

The two hydroxyl groups in ethylene glycol provide more locations for the formation of hydrogen bonds. The existence of more hydrogen bonds considerably increases the boiling point.

For a precipitation reaction to be useful in a gravimetric analysis, the product of the reaction must be insoluble. Is Kc > 1, < 1, or ≈ 1 for a useful precipitation reaction? The value of Kc will be much less than 1 for a useful precipitation reaction. The value of Kc will be much greater than 1 for a useful precipitation reaction. Kc ≈ 1

The value of Kc will be much greater than 1 for a useful precipitation reaction.

Explain why an egg cooks more slowly in boiling water in Denver than in New York City. (Hint: Consider the effect of temperature on reaction rate and the effect of pressure on boiling point.)

Water boils at a lower temperature at higher elevations The higher cooking temperature at sea level makes the rate of cooking faster and the time to completion shorter.

Water gas, a mixture of H2 and CO, is an important industrial fuel produced by the reaction of steam with red hot coke, essentially pure carbon. This is the expression for the reversible reaction C(s)+H2O(g)⇌CO(g)+H2(g)ΔH=131.30kJ What will happen to the concentration of each reactant and product at equilibrium if more C is added? [H2O] no change, [CO] no change, [H2] increases [H2O] no change, [CO] no change, [H2] no change [H2O] no change, [CO] decreases, [H2] no change [H2O] increases, [CO] increases, [H2] no chang

[H2O] no change, [CO] no change, [H2] no change

The hydronium ion concentration in a sample of rainwater is found to be 1.7 × 10-6 M at 25 °C. What is the concentration of hydroxide ions in the rainwater? [OH-] = 1.0 × 10-14; [1.7 × 10-6][OH-] = 1.0 × 10-13 [OH-] = 1.0 × 10-14; [1.6 × 10-6][OH-] = 1.0 × 10-12 [OH-] = 1.0 × 10-14; [1.7 × 10-6][OH-] = 1.0 × 10-14 [OH-] = 1.0 × 10-14; [1.6 × 10-6][OH-] = 1.0 × 10-14

[OH-] = 1.0 × 10-14; [1.7 × 10-6][OH-] = 1.0 × 10-14

CO2 in water is an example of: a gas in a liquid a solid in a liquid a gas in a gas a liquid in a gas

a gas in a liquid

Which of the following is a way in which the concentration of hydrazine, N2H4, could be increased in an equilibrium described by the following equation: N2(g)+2H2(g)⇌N2H4(g)ΔH=95kJ add N2 decrease the container volume heat the mixture all of these none of these

all of these

What is the term used to describe a species that may either donate or accept a proton in a Bronsted-Lowry acid-base reaction?

amphiprotic

This is the condensed formula for which compound? ch3-ch2-ch2-o-ch2-ch2-ch3 2,2-dimethyl-3-hexanol 3-ethoxybutane 2-ethoxybutane dipropyl ether

dipropyl ether

A spontaneous reaction is a reaction that has no natural tendency to occur and takes place only with the continual input of energy from an external source.

false

Air saturated with water is denser than dry air at the same temperature and pressure. True False

false

HCl is a weak acid that undergoes complete ionization in pure water.

false

The following 3 substances are either polar, nonpolar or ionic, which order is correct? vegetable oil, isopropyl alcohol, potassium bromide ionic, polar, ionic polar, ionic, nonpolar nonpolar, polar, ionic nonpolar, polar, nonpolar

nonpolar, polar, ionic

One of the important reactions in the biochemical pathway glycolysis is the reaction of glucose-6-phosphate (G6P) to form fructose-6-phosphate (F6P): Is the reaction spontaneous or nonspontaneous under standard thermodynamic conditions? nonspontaneous spontaneous

nonspontaneous

The ionization constant for water (Kw) is 2.9 × 10-14 at 40 °C. Calculate the pH, and pOH for pure water at 40 °C. pH = pOH = -log(1.70 × 10-6) = 6.769 = 6.77 pH = pOH = -log(1.70 × 10-7) = 6.769 = 6.77 pH = pOH = -log(1.70 × 10-8) = 6.769 = 6.77 pH = pOH = -log(1.70 × 10-5) = 6.769 = 6.77

pH = pOH = -log(1.70 × 10-7) = 6.769 = 6.77

How does the carbon-atom hybridization change when polyethylene is prepared from ethylene? The sp3 hybridization of ethylene changes to sp2 in polyethylene because all the bondsbecome single sigma bonds. The sp hybridization of ethylene changes to sp3 in polyethylene because all the bondsbecome single sigma bonds. The sp2 hybridization of ethylene changes to sp3 in polyethylene because all the bondsbecome single sigma bonds. The sp hybridization of ethylene changes to sp2 in polyethylene because all the bondsbecome single sigma bonds.

the sp2 hybridization of ethylene changes to sp3 in polyethylene because all the bondsbecome single sigma bonds.

An effect arises only when the number of moles of gaseous reactants in the equation that describes the equilibrium reaction differs from the number of moles of gaseous products. As the volume of a gaseous system decreases, the gases become compressed and the total number of molecules per unit volume increases, producing greater molar concentrations. This change in concentration represents a stress on the system, and the system will act to remove the stress, if possible. The pressure change will have an effect on the equilibrium only if the number of moles of gaseous reactants differs from the number of moles of gaseous products, shifting the condition of equilibrium to the side with the fewer number of moles.

true

Heat is added to boiling water. The temperature of the boiling water does not change. Is this description True (accurate) or False? The heat increases the kinetic energy of a limited number of molecules in the liquid water so that they have enough energy to escape into the gas phase. The escape of these molecules requires the additional energy be used to overcome intermolecular attractive forces in the liquid, and so the temperature of the remaining liquid does not increase. The amount of liquid water changes (decreases) as the additional heat causes some to change to a gas.

true

One explanation for the observations that ethanol, C2H5OH, is completely miscible with water and that ethanethiol, C2H5SH, is soluble only to the extent of 1.5 g per 100 mL of water could be that hydrogen bonds between water and C2H5OH are much stronger than the intermolecular attractions between water and C2H5SH.

true

The enthalpy of vaporization of water is larger than its enthalpy of fusion

true

The two types of reactions are distinguished by the arrow used in the equation: is used for equilibria reactions and is used for "one-way" reactions.

true

What is not a difference between ΔG and ΔG for a chemical change? None of these ΔG°: the (Gibbs) free energy change for a reaction in which the reagents and products are in their standard states (1 bar or 1 atm for gases, 1 M for solutions) at a specified temperature. ΔG: the (Gibbs) free energy change for any reaction under any set of conditions. ΔG: the (Gibbs) free energy change for any reaction under a particular set of conditions.

ΔG: the (Gibbs) free energy change for any reaction under a particular set of conditions.

redict the sign of the entropy change when exhaled breath forms fog on a cold morning. ΔS < 0 ΔS = 0 ΔS > 0

ΔS < 0

Predict the sign of the entropy change when an ice cube is warmed to near its melting point. ΔS < 0 ΔS = 0 ΔS > 0

ΔS > 0

For this pair of standard cell potential and electron stoichiometry values below, calculate a corresponding standard free energy change (kJ). +0.434 V, n = 2

−83.7 kJ/mol