Need someone to take general chemistry 2 college course exam

Need someone to take general chemistry 2 college course exam

INSTRUCTIO enter your answers to each exam question on the answer sheet sent to you by typing in your answer.
For problems 1 and 2 from the short answer section, and problems 1 and 2 from the problems section, attach
your work to the answer sheet (or send separately) so that you show how you arrived at your answer.
Please remain logged in on ZOOM until after you have sent me your answer sheet and attached work.
During the exam, keep your audio muted and your video turned off unless requested to do otherwise.
If you have questions during the exam, send them to me privately through chat. I will answer clarification
questions but will not assist you in figuring out how to do a problem.
Send your answer sheet and attached work to my email address joensj@fiu.edu
Unless otherwise arranged with me, your answers are due by NOON.
Good luck!

Need someone to take general chemistry 2 college course exam

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FORMULA SHEET (tear off)
NA = 6.022 x 10 23 C = (5/9) (F – 32) F = (
9/5)(C) + 32
1 amu = 1.661 x 10-27 kg C = K – 273.15 K = C + 273.15
1 atm = 760 torr = 760 mm Hg 1 atm = 1.013 bar pV = nRT
R = 0.08206 Latm/molK 1 Latm = 101.3 J
R = 8.314 J/molK 1 J = 1 kgm2/s2
pA = XA pA [B] = k pB pA = XBpA
Tb = Kb mB Tf = Kf mB  = [B]RT
Kp = KC (RT) ng
H = U + pV G = H – TS
Grxn = Grxn + RT ln Q ln K = – Grxn/RT
If ax2 + bx + c = 0, then x = ( – b  [b2 – 4ac]1/2 )
2a
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Part 1. Multiple choice. Circle the letter corresponding to the correct answer. There is one and only one correct
answer per problem. [4 points each]
1) A solution is formed by adding 2.0 g of carbon tetrachloride (CCl4) and 10.0 g of carbon disulfide (CS2) to 200.0 g
of cyclohexane (C6H12). Which of the substances in the solution is classified as a solute?
a) carbon tetrachloride (CCl4)
b) carbon disulfide (CS2)
c) cyclohexane (C6H12)
d) both a and b
e) both a and b and c
2) For a particular liquid solution of benzene (C6H6, MW = 78.1 g/mol) and n-hexane (C6H14, MW = 86.2 g/mol) the
mole fraction of benzene in the solution is XB = 0.182 Which of the following cannot be calculated from the
information given above?
a) The molarity of benzene in the solution
b) The molality of benzene in the solution
c) The percent by mass of benzene in the solution
d) None of the above can be calculated from the given information
e) All of the above can be calculated from the given information
3) A solution is formed by dissolving a nonvolatile solute in a volatile solvent. Which of the following statements
about the solution is true?
a) The boiling point for the solution is higher than the boiling point for the pure liquid
b) The freezing point for the solution is higher than the freezing point for the pure liquid
c) The vapor pressure of solvent above the solution is higher than the vapor pressure of solvent above the
pure liquid
d) Both a and b
e) Both a and b and c
4) The van’t Hoff factor for the ionic compound vanadium II nitrate ((NO3)2) in water is
a) i = 1
b) i = 2
c) i = 3
d) i = 4
e) i > 4
5) A glass of liquid water at room temperature sitting on top of a table will not spontaneously form ice and hot water.
This is because the formation of ice and hot water would
a) violate the First Law of Thermodynamics
b) violate the Second Law of Thermodynamics
c) violate the Third Law of Thermodynamics
d) violate both the First and the Second Laws of Thermodynamics
e) violate all three of the laws of thermodynamics
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6) For a chemical reaction taking place for standard conditions, which of the following could be true?
a) Srxn > 0
b) Srxn < 0
c) Hrxn > 0
d) Hrxn < 0
e) All of the above could be true
7) Consider the following three chemical reactions, all taking place at T = 25.0 C.
i. HCHO(g)  CO(g) + H2(g)
ii. 2 H2(g) + O2(g)  2 H2O() iii. MgCO3(s)  MgO(s) + CO2(g)
For which of these reactions would we expect Srxn to be large and positive?
a) Reaction i. only
b) Reaction ii. only
c) Reaction iii. only
d) Both reaction i. and reaction iii.
e) Both reaction ii. and reaction iii.
8) For which of the following pure chemical substances is Gf = 0.0 kJ/mol?
a) C2(g)
b) N2(g)
c) SO(g)
d) both b and c
e) both a and b and c
9) Which of the following changes will cause a change in the numerical value for the equilibrium constant for a
chemical reaction?
a) Changing the temperature
b) Changing the pressure
c) Changing the volume
d) both b and c
e) both a and b and c
10) Consider the following three chemical reactions, all taking place at T = 25.0 C.
i. Cl2(g)  2 Cl(g) KC = 6.4 x 10 -39
ii. Cl2(g) + 2 NO(g)  2 NOCl(g) KC = 3.7 x 10 8
iii. Cl2(g) + 2 NO2(g)  2 NO2Cl(g) KC = 1.8
For which of the above reactions will products be greatly favored over reactants at equilibrium?
a) Reaction i. only
b) Reaction ii. only
c) Reaction iii. only
d) Both reaction i. and reaction ii.
e) Both reaction i. and reaction ii. and reaction iii.
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11) In a closed system of constant volume and temperature the following chemical reaction takes place.
A2(g) + B2(g)  2 AB(g)
For the conditions of the system it is found that KC = 420. and QC = 18. As the system approaches equilibrium,
which of the following will occur?
a) the moles of A2 will increase
b) the moles of B2 will increase
c) the moles of AB will increase
d) both a and b
e) the moles of A2, B2, and AB will remain constant
12) Experimentally it is observed that the solubility of a gas in water usually decreases as temperature increases. The
reason for this is that when gases are dissolved in water
a) Ssoln > 0 is usually true
b) Ssoln < 0 is usually true
c) Hsoln > 0 is usually true
d) Hsoln < 0 is usually true
e) Gsoln < 0 is usually true
Part 2. Short answer questions.
1. (10 points) Two volatile liquids A and B form an ideal solution at a temperature T. The vapor pressure of pure A
at that temperature is pA = 480. torr. For a solution with XA = 0.40, it is found that the total pressure above the
liquid solution is ptotal = pA + pB = 620. torr. Based on this information, find the value for pB, the vapor pressure of
pure B at temperature T.
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2. (10 points) A solution is formed at T = 25. C by dissolving 2.85 g of glucose (C6H12O6, MW = 180.2 g/mol), a
nonvolatile and nonionizing solute, in water (H2O, MW = 18.02 g/mol). The final volume of the solution is V =
200.0 mL. Based on this information, find the osmotic pressure of the solution. Give your final answer in units of
torr.
3. For a particular chemical reaction it is found that Ssurr = 48.2 J/molK and Suniv = – 18.9 J/molK.
a) What is the value for Ssyst for the reaction? (4 points) ____________________
b) Is the reaction spontaneous (yes or no)? (4 points) ________________
4) Consider the chemical reaction
CO2(g) + CS2()  2 COS(g)
A closed system at temperature T is initially at equilibrium. For each of the following changes predict whether the
change will cause the number of moles of CO2 in the system to increase, remain constant, or decrease. (4 points each)
a) Adding 0.200 moles of COS(g) to the system
moles CO2 will moles CO2 will moles CO2 will
increase remain constant decrease
b) Decreasing the volume of the system by 500.0 mL while keeping temperature constant
moles CO2 will moles CO2 will moles CO2 will
increase remain constant decrease
5. (6 points) Give the correctly balanced formation reaction for titanium III carbonate, Ti(CO3)3(s).
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Part 3. Problems
1. (15 points) Based on the thermochemical data given below, find the numerical values for Grxn and K for the
following reaction. You may assume T = 25.0 C.
C8H18() + 2 H2(g)  C4H10(g) + 2 C2H6(g)
Substance Hf S Gf
(kJ/mol) (J/molK) (kJ/mol)
C2H6(g) – 84.7 229.6 – 32.8
C4H10(g) – 126.2 310.2 – 17.0
C8H18() – 249.9 361.1 + 6.4 H2(g) 0.0 130.7 0.0
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2. (15 points) For the chemical reaction
H2(g) + I2(g)  2 HI(g)
the experimental value for the equilibrium constant is KC = 2.2 at some temperature T.
For a particular system the initial concentrations of H2 and HI are [H2] = 0.300 M and [HI] = 0.200 M. No
I2 is initially present in the system. Find [I2] the concentration of iodine, when equilibrium is reached.

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Author Since: November 30, 2020