Final Exam
-Which of these weak acid solutions has the greatest percent ionization? -Which solution has the lowest (most acidic) pH? -0.900 M HC2H3O2 -4.50 M HC2H3O2 -0.0900 MM HC2H3O2
-0.0900 MM HC2H3O2 -4.50 M HC2H3O2
An aqueous NaCl solution is made using 115g of NaCl diluted to a total solution volume of 1.05 L. -Calculate the molarity of the solution. -Calculate the molality of the solution. (Assume a density of 1.08 g/mL for the solution.) -Calculate the mass percent of the solution. (Assume a density of 1.08 g/mL for the solution.)
-1.87 mol/L -1.9 mol/kg -10.1%
Describe catalyst and its function. Check all that apply. -A catalyst is a substance that is not used up during a reaction. -A catalyst does not affect the products obtained in the reaction. -A catalyst is a substance that is used up during a reaction. -A catalyst changes the pathway of the reactants to products in a way that reduces the activation energy and speeds up the reaction. -A catalyst does not change the pathway of the reactants to products in a way that reduces the activation energy and lowers the speed of the reaction. -A catalyst affects the products obtained in the reaction.
-A catalyst is a substance that is not used up during a reaction. -A catalyst does not affect the products obtained in the reaction. -A catalyst changes the pathway of the reactants to products in a way that reduces the activation energy and speeds up the reaction.
Consider the following reaction: N2O4(g) ⇌ 2NO2(g), Kc = 0.36 at 2000∘ The reaction mixture initially contains only the reactant, [N2O4] = 0.0260M, and no NO2. -Find the equilibrium concentration of N2O4. -Find the equilibrium concentration of NO2.
-[N2O4] = 0.005 M -[NO2] = 0.042 M
The following reaction was monitored as a function of time: AB→A+B A plot of 1/[AB] versus time yields a straight line with slope 5.9×10^−2 (M⋅s)^−1. -What is the value of the rate constant (k) for this reaction at this temperature? -Write the rate law for the reaction. -What is the half-life when the initial concentration is 0.51 M? -If the initial concentration of AB is 0.220 M, and the reaction mixture initially contains no products, what are the concentrations of A and B after 80 s?
-k = 5.9×10^−2 M^−1 s^−1 -Rate = k[AB]^2 -t1/2 = 33 s -[A],[B] = 0.11,0.11 M
The following reaction is first order in N2O5: N2O5(g) → NO3(g) + NO2(g) The rate constant for the reaction at a certain temperature is 0.053/s. -Calculate the rate of the reaction when [N2O5]= 5.2×10^−2 M. -What would the rate of the reaction be at the same concentration as in Part A if the reaction were zero order?
-rate = 2.8×10^−3 M/s -rate = 5.3×10^−2 M/s
The data below were collected for the following reaction: CH3Cl(g) + 3Cl2(g) → CCl4(g) + 3HCl(g) [CH3Cl](M) [Cl2](M) Initial rate (M/s) 0.050 0.050 0.014 0.100 0.050 0.029 0.100 0.100 0.041 0.200 0.200 0.115 -Choose an expression for the reaction rate law. -Calculate the value of the rate constant, k. -What is the overall order of the reaction?
-rate=k[CH3Cl][Cl2]^1/2 -k = 1.3 M^−1/2 s^−1 -n = 1.5
What are the units of k in the following rate law? Rate = k[X][Y]^3
1/(M^3 s)
What mass of glucose (C6H12O6) should be dissolved in 10.5 kg of water to obtain a solution with a freezing point of -5.1∘C?
5.2 kg
Calculate the pOH of a nitrous acid solution that contains 3.9 × 10^-9 M H3O+ at 25°C.
5.59
Identify the compound that does NOT have dipole-dipole forces as its strongest force. -CH3Br -CO2 -CH2I2 -CCCl3 -CH3OCH3
CO2
Which of the following substances would you predict to have the highest ΔHvap? -SiF4 -H2O -Cl2 -Kr -H2
H2O
Identify an homogeneous catalyst. -Pd with methane -H2SO4 with concentrated HCl -SO2 over vanadium (V) oxide -Pt in H2 gas -N2 catalyzed by Fe
H2SO4 with concentrated HCl
What are the units of k in the following rate law? Rate = k[X][Y]^1/2
M^-1/2 s^-1
Choose the pair of substances that are most likely to form a homogeneous solution. -NF3 and SO2 -CBr4 and SI2 -NH2CH3 and CH4 -CO and C5H12
NF3 and SO2
What happens to the concentrations of reactants and products during a chemical reaction?
The concentration of reactants decreases and the concentration of products increases during a chemical reaction.
For a reaction that follows the general rate law, Rate = k[A][B]^2, what will happen to the rate of reaction if the concentration of B is increased by a factor of 5.00?
The rate will increase by a factor of 25.0
Given the following rate law, how does the rate of reaction change if the concentration of Y is doubled? Rate = k[X][Y]^2
The reaction will increase by a factor of 4.
Calculate the amount of heat (in kilojoules) required to vaporize 2.20 kg of water at its boiling point (ΔHvap = 40.7 kJ/mol at 100∘C).
q = 4970 kJ
For the reaction 2A+B→C, the initial rate was measured at several different reactant concentrations. From the tabulated data, determine the rate law for the reaction. [A](M) [B](M) Initial Rate (M/s) 0.050 0.050 0.035 0.10 0.05 0.070 0.20 0.10 0.28
rate = k[A][B]
Which rate law is termolecular? -rate = k[A][B] -rate = k[A]^2 -rate = k[A]^2[B] -rate = k[A] -rate = k[A][B][C][D]
rate = k[A]^2[B]
A first-order reaction has a half-life of 27.8 s . How long does it take for the concentration of the reactant in the reaction to fall to one-eighth of its initial value?
t = 83.4 s
The enthalpy of solution for LiCl is -37.00 kJ/mol. What can you conclude about the relative magnitudes of the absolute values of ΔHsolute and ΔHhydration, where ΔHsolute is the heat associated with separating the solute particles and ΔHhydration is the heat associated with dissolving the solute particles in water? -ΔHsolute| < |ΔHhydration| -|ΔHsolute| > |ΔHhydration| -|ΔHsolute| = |ΔHhydration| -none of the above (nothing can be concluded about the relative magnitudes)
ΔHsoln= ΔHsolute + ΔHhydration Since ΔHsoln<0, |ΔHsolute| < |ΔHhydration|
Calculate the osmotic pressure (in atmospheres) of a solution containing 2.20g ethylene glycol (C2H6O2) in 52.0 mL of solution at 25∘C.
Π = 16.7 atm
A solution containing ethylene glycol and water has a vapor pressure of 7.89 torr at 10∘C. Pure water has a vapor pressure of 9.21 torr at 10∘C. What is the mole fraction of ethylene glycol in the solution?
χ = 0.143
For a particular reaction in which A → products, doubling the concentration of A has no effect on the reaction rate. What is the order of the reaction?
0
A 600.0-mL sample of pure water is allowed to come to equilibrium with pure oxygen gas at a pressure of 920 mmHg. What mass of oxygen gas dissolves in the water (The Henry's law constant for oxygen gas at 25∘C is 1.3×10−3M/atm)?
0.030g
The decomposition of N2O5 in solution in carbon tetrachloride proceeds via the reaction 2N2O5(soln) → 4 NO2(soln) + O2(soln) The reaction is first order and has a rate constant of 4.82 × 10^-3 s^-1 at 64°C. If the reaction is initiated with 0.075 mol in a 1.00-L vessel, how many moles remain after 151 s?
0.036 moles
The elementary reaction 2NO2(g) → 2 NO(g) + O2(g) is second order in NO2 and the rate constant at 720 K is 2.88 × 10^1 M^-1 s^-1. The reaction half-life at this temperature when [NO2]0 = 0.45 M is ________ s.
0.077
The combustion of ethylene proceeds by the reaction C2H4(g) + 3 O2(g) → 2 CO2(g) + 2 H2O(g) When the rate of disappearance of O2 is 0.13 M s^-1, the rate of appearance of CO2 is ________ M s^-1.
0.087
The rate of disappearance of HBr in the gas phase reaction 2 HBr(g) → H2(g) + Br2(g) is 0.221 M s^-1 at 150°C. The rate of reaction is ________ M s^-1.
0.111
A solution contains 20.4g glucose (C6H12O6) dissolved in 0.640-L of water. What is the molality of the solution (Assume a density of 1.00 g/mL for water)?
0.177m
The reaction X → products is second order in X and has a rate constant of 0.035 M^−1 s^−1. If a reaction mixture is initially 0.80 M in X, what is the concentration of X after 120. seconds?
0.18M
For a particular reaction in which A → products, doubling the concentration of A causes the reaction rate to double. What is the order of the reaction?
1
The rate constant for a first-order reaction is 0.54 s^-1. What is the half-life of this reaction if the initial concentration is 0.27 M?
1.3s
A sodium nitrate solution is 14.1% NaNO3 by mass and has a density of 1.02 g/mL. Calculate the molarity of the solution.
1.69M
Consider the equation for the decomposition of NO2, NO2(g)→NO(g)+O(g) The graph of 1/[NO2] versus time (s) is 1/[NO2] = 0.225x +100 Use the graph and the best fitting line to predict the concentration of NO2 at 1900 s.
1.7×10^−3 M
What are the units of k in the following rate law? Rate = k[X]^3[Y]
1/(M^3 s)
The reaction A(g) ⇌2 B(g)A has an equilibrium constant of K=0.010. What is the equilibrium constant for the reaction B(g) ⇌ 1/2 A(g)?
10
Acetic acid has a normal boiling point of 118∘C and a ΔHvap of 23.4 kJ/mol. What is the vapor pressure (in mmHg) of acetic acid at 35∘C?
109 mmHg
A solution contains a mixture of two volatile substances A and B. The mole fraction of substance A is 0.39. At 32∘C the vapor pressure of pure A is 95 mmHg and the vapor pressure of pure B is 141 mmHg. What is the total vapor pressure of the solution at this temperature?
123 mmHg
How many compounds, of the ones listed below, have hydrogen bonding? -CH3(CH2)4NH2 -CH3(CH2)2NH(CH2)4CH3 -(CH3CH2)2N(CH2)2CH3
2
A 2.5 m aqueous solution of an ionic compound with the formula MX2 has a boiling point of 102.7∘C. Calculate the van't Hoff factor (i) for MX2 at this concentration.
2.1
Determine the amount of heat (in kJ) required to vaporize 1.05 kg of water at its boiling point. For water, ΔHvap = 40.7 kJ/mol (at 100∘C).
2.37 × 10^3 kJ
For the reaction 2A+B→C2A+B→C, the initial rate is measured at several different reactant concentrations. [A](M) [B](M) Initial Rate (M/s) 0.06 0.06 0.045 0.12 0.06 0.090 0.24 0.12 0.72
210
How many half-lives are required for the concentration of reactant to decrease to 12.5% of its original value?
3
The osmotic pressure of a solution containing 26.6 mg of an unknown protein in 50.0 mL of solution is 2.82 mmHg at 25∘C. Determine the molar mass of the protein.
3.51 × 10^3 g/mol
Consider the following reaction: O3(g)→O2(g)+O(g) Using the results of the Arrhenius analysis (Ea=93.1 kJ/mol and A=4.36×10^11 M⋅s^−1), predict the rate constant at 303 K .
3.88 × 10^−5 L/(mol⋅s)
Determine the normal boiling point of a substance whose vapor pressure is 55.1 mm Hg at 35°C and has a ΔHvap of 32.1 kJ/mol.
390K
What is the overall order of the following reaction, given the rate law? 2NO(g) + H2(g) → N2(g) + 2 H2O(g) Rate = k[NO]^2[H2]
3rd Order
What is the overall order of the following reaction, given the rate law? 2X + 3Y → 2Z Rate = k[X]^2[Y]
3rd Order
The isomerization of methylisonitrile to acetonitrile CH3NC(g) → CH3CN(g) is first order in CH3NC. The rate constant for the reaction is 1.43 × 10-4 s^-1 at 483 K. The half-life of the reaction when the initial [CH3NC] is 0.030 M is ________ s.
4.83 × 10^3
A particular first-order reaction has a rate constant of 1.35 × 10^2 s^-1 at 25.0°C. What is the magnitude of k at 75.0°C if Ea = 64.5 kJ/mol?
5.69 × 10^3 s^-1
Consider the equation for the decomposition of SO2Cl2, SO2Cl2(g)→SO2(g)+Cl2(g) The graph of ln[SO2Cl2]ln[SO2Cl2] versus time (s) is: ln [SO2Cl2] = -0.000290t - 2.30 Use the graph and the best fitting line to predict the concentration of SO2Cl2 at 1600 s.
6.3 × 10^−2 M
What is the hydroxide ion concentration and the pH for a hydrochloric acid solution that has a hydronium ion concentration of 1.50 × 10^-2 M?
6.67 × 10-^13 M, 1.824
The enthalpy change for converting 10.0 g of ice at -50.0°C to water at 60.0°C is _____ kJ. The specific heats of ice, water, and steam are 2.09 J/gK, 4.18 J/gK, and 1.84 J/gK, respectively. For H2O, ΔHfus = 6.01 kJ/mol, and ΔHvap = 40.67 kJ/mol.
6.89 kJ
The rate constant of a reaction is measured at different temperatures. A plot of the natural log of the rate constant as a function of the inverse of the temperature (in kelvins) yields a straight line with a slope of −8.35 × 10^3 K. What is the activation energy (Ea) for the reaction?
69.4 kJ
The reaction shown here has a Kp = 4.0×10^2 at 825 K. CH4(g) + CO2(g) ⇌ 2CO(g) + 2H2(g) Find Kc for the reaction at this temperature.
8.7 × 10^−2
Given the following balanced equation, determine the rate of reaction with respect to [Cl2]. If the rate of Cl2 loss is 4.60 × 10^-2 M/s, what is the rate of formation of NOCl? 2NO(g) + Cl2(g) → 2NOCl(g)
9.20 × 10^-2 M/s
Which statement is true regarding the function of a catalyst in a chemical reaction? -A catalyst provides an alternate mechanism for the reaction in which the rate-determining step has a higher activation energy. -Enzymes are biological catalysts capable of decreasing the rate of specific biochemical reactions by many orders of magnitude. -A catalyst is consumed by the reaction. -A catalyst increases the rate of a reaction.
A catalyst is a substance that increases the rate of a chemical reaction but is not consumed by the reaction.
A sample of the substance in the phase diagram is initially at 175∘C and 925 mmHg. The triple point is at 855 mmHg and 145∘C. What phase transition occurs when the pressure is decreased to 760 mmHg at constant temperature? -liquid to gas -solid to gas -solid to liquid -liquid to solid
At 175∘C and 925 mmHg, this substance is a liquid. When the pressure is decreased, the vaporization curve is crossed and the substance becomes a gas.
A substance has a triple point at −24.5∘C and 225 mmHg. What is most likely to happen to a solid sample of the substance as it is warmed from −35∘C to 0∘C at a pressure of 220 mmHg? -The solid will melt into a liquid. -Nothing (the solid will remain as a solid). -The solid will sublime into a gas.
Because the pressure is below the triple point, the liquid state is not stable. At −35∘C, the substance is a solid and will sublime when it is heated.
The enthalpy of solution for ammonium nitrate is +25.7 kJ/mol. What can you conclude about the relative magnitudes of ΔHsolute and ΔHhydration? -|ΔHsolute|<|ΔHhydration| -|ΔHsolute|>|ΔHhydration| -|ΔHsolute|=|ΔHhydration| -None of the above (nothing can be concluded about the relative magnitudes)
Because ΔHsoln is positive for ammonium nitrate, the absolute value of the negative term (ΔHhydration) must be smaller than the absolute value of the positive term (ΔHsolute). |ΔHsolute| > |ΔHhydration|.
An aqueous solution is saturated in both potassium chlorate and carbon dioxide gas at room temperature. What happens when the solution is warmed to 85∘C? -Potassium chlorate precipitates out of solution. -Carbon dioxide bubbles out of solution. -Potassium chlorate precipitates out of solution and carbon dioxide bubbles out of solution. -Nothing happens; all of the potassium chlorate and the carbon dioxide remain dissolved in solution.
Carbon dioxide bubbles out of solution. The solubility of gases like CO2 decreases with increasing temperature. Most ionic compounds become more soluble as the temperature increases.
Place the following compounds in order of increasing boiling point. -LiBr -Cl2 -CH3OH
Cl2 < CH3OH < LiBr
The decomposition of NH4HS is endothermic: NH4HS(s) ⇌ NH3(g) + H2S(g) Which change to an equilibrium mixture of this reaction results in the formation of more H2S? -a decrease in the volume of the reaction vessel (at constant temperature) -an increase in the amount of NH4HS in the reaction vessel -removing NH3 from the reaction mixture as it forms -all of the above
Decreasing the concentration of NH3 shifts the reaction to generate more products, forming more H2S.
An aqueous solution is in equilibrium with a gaseous mixture containing an equal number of moles of oxygen, nitrogen, and helium. Rank the relative concentrations of each gas in the aqueous solution from highest to lowest. -[N2] > [He] > [O2] -[N2] > [O2] > [He] -[He] > [N2] > [O2 -[O2] > [N2] > [He]
For Henry's law, Sgas = kH x Pgas x Pgas is the same for each of the three gases. The value of the Henry's law constant, kH, increases with the molar mass of the gas, so [O2] > [N2] > [He].
Which pair is not a conjugate acid-base pair? -H3PO3; H3PO4 -H2PO4−; HPO4 2- (CH3)3N; (CH3)3NH+
H3PO3 and H3PO4 are both acids. Therefore, this is not a conjugate acid-base pair.
Which molecules have dipole-dipole forces? -HBr -CI4 (carbon tetraiodide) -CH3F
HBr & CH3F Dipole-dipole forces occur between polar molecules (i.e., molecules with a permanent dipole). A molecule is polar when two conditions are met: (1) it has at least one polar bond, and (2) all polar bonds form a net dipole moment. For the two polar molecules, the δ+δ+ charge exists around the hydrogen atom because it is electron deficient, and the δ−δ− charge exists opposite hydrogen because the electronegative atoms cause those regions to be electron-rich. Although the bonds in CI4 (carbon tetraiodide) are polar, the tetrahedral geometry causes all dipole moments to cancel, so it is a nonpolar molecule and unable to participate in dipole-dipole interactions. Note that the dipole moments do not cancel in CH3F despite the tetrahedral geometry because one of the bonds is a C−H bond, which makes it asymmetric.
Choose the substance with the highest viscosity. -(CH3CH2)2CO -C6H14 -HOCH2CH2CH2CH2OH -CF4 -C2H4Br2
HOCH2CH2CH2CH2OH
Choose the substance with the highest surface tension. -CH2Cl2 -HOCH2CH2OH -CH3CH2CH2CH3 -CH3CH2Br -CH3CH2CH2OH
HOCH2CH2OH
Express the equilibrium constant for the following reaction. 6 P4O10(s) ⇌ 6 P4(s) + 30 O2(g)
K = [O2]^30
Consider the following reaction: CO(g) + 2H2(g) ⇌ CH3OH(g) The reaction between CO and H2 is carried out at a specific temperature with initial concentrations of CO = 0.27 M and H2H2 = 0.55 M. At equilibrium, the concentration of CH3OH is 0.10 M. Find the equilibrium constant at this temperature.
Kc = 4.8
Consider the chemical equation and equilibrium constant at 25∘C: H2(g)+I2(g)⇌2HI(g), K=6.2×10^2 Calculate the equilibrium constant for the following reaction at 25∘C: HI(g) ⇌ 1/2 H2(g)+1/2 I2(g)
K′ = 4.0 × 10^−2
One of these substances is a liquid at room temperature. Which one? -CF4 -BF3 -CH3OH -SiH4
Methanol (CH3OH) contains hydrogen directly bonded to oxygen, so it has hydrogen bonding. Hydrogen bonding is a strong intermolecular force that makes this substance a liquid at room temperature.
Which of the following statements is FALSE? -The rate of vaporization increases with increasing temperature. -The rate of vaporization increases with decreasing strength of intermolecular forces. -The rate of vaporization increases with increasing surface area. -Molecules with hydrogen bonding are more volatile than compounds with dipole-dipole forces. -None of the above is false.
Molecules with hydrogen bonding are more volatile than compounds with dipole-dipole forces.
Propane has a normal boiling point of −42.0∘C and a heat of vaporization (ΔHvap) of 19.04 kJ/mol. What is the vapor pressure of propane at 40.0∘C?
P = 1.02×10^4 torr
Calculate the vapor pressure at 25∘C of a solution containing 55.8g ethylene glycol (HOCH2CH2OH) and 274.8g water. The vapor pressure of pure water at 25∘C is 23.8 torr.
Psolution = 22.5 torr
Given the following balanced equation, determine the rate of reaction with respect to [O2]. 2O3(g) → 3 O2(g)
Rate = +1/3 Δ[O2]/Δt
Determine the rate law and the value of k for the following reaction using the data provided. 2N2O5(g) → 4NO2(g) + O2(g) [N2O5]i (M) Initial Rate (M/s) 0.093 4.84 × 10^-4 0.186 9.67 × 10^-4 0.279 1.45 × 10^-3
Rate = 5.2 × 10^-3 s^-1 [N2O5]
Given the following proposed mechanism, predict the rate law for the overall reaction. A2 + 2 B → 2 AB (overall reaction) Mechanism A2 ⇌ 2 A fast A + B → AB slow
Rate = k[A2]^1/2[B]
Reaction A and reaction B have identical frequency factors. However, reaction B has a higher activation energy than reaction A. Which reaction has a greater rate constant at room temperature?
Reaction A has a faster rate because it has a lower activation energy; therefore, the exponential factor is larger at a given temperature, making the rate constant larger. (With a larger rate constant and the same initial concentration, the rate is faster.)
Determine the solubility of nitrogen in water at 25∘C exposed to air at 1.0 atm. Assume a partial pressure for nitrogen of 0.78 atm. (kH,N2 = 6.1×10^−4 M/atm).
SN2 = 4.8×10^−4 M
Based on the expected intermolecular forces, which halogen has the lowest boiling point? -I2 -F2 -Br2 -Cl2
Since boiling point decreases with decreasing strength of intermolecular forces, and since the halogens only have the dispersion force (which decreases with decreasing molar mass), the boiling points of the halogens decrease with decreasing molar mass. Fluorine (F2) has the lowest molar mass of the halogens in this list, so it has the lowest boiling point.
Which compound is most soluble in hexane (C6H14)? -NH3 -CCl4 -CH3OH -H2O
Since hexane is a nonpolar solvent, nonpolar compounds, such as CCl4, have the highest solubility. The other compounds listed are very polar and capable of hydrogen bonding.
Calculate the boiling point of a 3.66 m aqueous sucrose solution.
Tb = 101.874∘C
Which substance experiences dipole-dipole forces? -BF3 -CS2 -NF3 -CCl4
The N−F bond is polar and its geometry is trigonal pyramidal. Therefore, the three polar bonds sum to an overall dipole moment and NF3 experiences dipole-dipole forces.
What is the rate law for the elementary step Cl + CO → ClCO?
The generic chemical equation of the elementary step is A + B → products. The elementary step is bimolecular. The rate law for the bimolecular elementary step is Rate=k[A][B]. The correct law for Cl + CO → ClCO is the following: Rate=k[Cl][CO]
A decomposition reaction has a half-life that is directly proportional to the initial concentration of the reactant. What is the order of the reaction?
The half-life of a zero-order reaction is directly proportional to the initial concentration of the reactant.
Why isn't heptanol (CH3CH2CH2CH2CH2CH2CH2OH) very soluble in water?
The heptanol contains a polar -OH group that forms a hydrogen bond with water and a long, nonpolar alkyl chain that exhibits dispersion forces. The majority of this molecule will not hydrogen bond with water molecules, making it difficult to dissolve.
Consider the following reaction and its equilibrium constant: 4CuO(s) + CH4(g) ⇌ CO2(g) + 4 Cu(s) + 2 H2O(g) Kc = 1.10 A reaction mixture contains 0.20 M CH4, 0.70 M CO2 and 1.5 M H2O. Which of the following statements is TRUE concerning this system? -The equilibrium constant will increase. -The reaction quotient will increase. -The reaction will shift in the direction of reactants. -The reaction will shift in the direction of products. -The system is at equilibrium.
The reaction will shift in the direction of reactants.
The mechanism shown here is proposed for the gas phase reaction, O2 + 2NO(g)→2NO2. 2NO2NO ⇌k1/k-1 N2O2 Fast O2+N2O2→2NO2 Slow What rate law does the mechanism predict?
Using the slow step, rate= k[O2][N2O2]. The intermediates cannot appear in the rate law, so use the first step to determine k1[NO]2=k−1[N2O2]. Substituting into the initial equation, rate=k[O2][N2O2] = k1/k−1 [O2][NO]^2 = k[O2][NO]^2.
A water sample contains the pollutant chlorobenzene with a concentration of 14 ppb (by mass). What volume of this water contains 4.66 × 10^2 mg of chlorobenzene (Assume a density of 1.00 g/mL)?
V = 3.3 × 10^4 L
Which property of a liquid increases with increasing temperature? -surface tension -vapor pressure -viscosity -none of the above
Vapor pressure increases with increasing temperature, since more of the particles have sufficient energy to leave the liquid phase as temperature increases.
Under which circumstances are Kp and Kc equal for the reaction aA(g) + bB(g) ⇌ cC(g) +dD(g)? -when the reaction is reversible -when a + b = c +d -when the equilibrium constant is large
When a + b = c + d, the quantity Δn is zero so that Kp=Kc(RT)^0. Since (RT)^0 is equal to 1, Kp = Kc.
Identify the compounds that are soluble in both water and hexane. -methanol and pentane1 -1-butanol and 1-pentanol -1-propanol and 1-butanol -ethanol and 1-propanol -ethanol and 1-pentanol
ethanol and 1-propanol
What type of intermolecular force causes the dissolution of KBr in water?
ion-Dipole Forces
The reaction between nitrogen dioxide and carbon monoxide is NO2(g)+CO(g)→NO(g)+CO2(g) The rate constant at 701 K is measured as 2.57 M^−1⋅s^−1 and that at 895 K is measured as 567 M^−1⋅s^−1. Use the value of the activation energy (Ea=1.50×10^2 kJ/mol) and the given rate constant of the reaction at either of the two temperatures to predict the rate constant at 495 K.
k = 4.78×10^−5 M^−1⋅s^−1
Which of the following represents the integrated rate law for a first-order reaction? -1/[A]o − 1/[A]t = −kt -ln(k1/k2) = ln(Ea/R)(1T) + lnA -k = Ae^(Ea/RT) -[A]o − [A]t= −kt -ln([A]t/[A]o) = −kt
ln([A]t/[A]o) = −kt
What mass of sucrose (C12H22O11), in grams, is contained in 355 mL (12 oz) of a soft drink that is 11.6% sucrose by mass (Assume a density of 1.03 g/mL)?
m = 42.4 g
