Answers created by Truong-Son N.

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• On what quantum level should #g# orbitals start to exist?
  
• Why should we wear goggles in lab? They're so uncomfortable, and they keep fogging up!! Give me one reason why...
  
• If excess of #AgNO_"3"# solution is added to 100 ml of 0.024 M solution of dichlorobis (ethylene diamine) cobalt (III) chloride, how many moles of #AgCl# will be precipitated??
  
• Effective atomic number of #Fe# in #Fe_"2"(CO)_"9"# is ??
  
• The color of light absorbed by an aqueous solution of #CuSO_"4"# is??
  
• What is the #"pH"# of a solution with #["OH"^(-)] = 3.9 xx 10^(-8) "M"#?
  
• What is the #"pOH"# of a solution containing #7.5 xx 10^(-2) "M H"^(+)#?
  
• What is the #"pOH"# for a solution of #4.8 xx 10^(-10) "M"# #"H"^(+)#?
  
• If the concentration of #"SO"_2# in air is #"0.5 ppm"#, what is the percent by mass?
  
• Draw the graph of the functions listed below?
  
• Do solid particles vibrate?
  
• Which of the following anions would precipitate the most in the reaction of sodium salts with magnesium chloride? What could be done to increase the solubility of the precipitate?
  
• What is the new boiling point for an aqueous #"0.743 molal"# solution of #"KCl"#? #K_b = 0.512^@ "C/m"#
  
• What is the freezing point for an aqueous solution with #"0.195 molal"# #"K"_2"S"# dissolved in it? Assume #100%# dissociation. #K_f = 1.86^@ "C/m"#.
  
• What is the boiling point for a 3 molal #"CaCl"_2# aqueous solution? #K_b = 0.512^@ "C/m"#.
  
• True or false? The maximum covalency in 2nd-period elements is #4#. Why is this true if fluorine can only make one bond?
  
• What two actinides occur naturally on on Earth?
  
• The frequency of radiation emitted when electron falls from n=4 to n=1 in a hydrogen atom will be (given ionization energy of H = #2.18 xx 10^(-18) "J/atom"# and #h = 6.626 xx 10^(-34) "J"cdot"s"#)?
  
• How does gas solubility change in the following scenarios, relative to the appropriate reference state?
  
• What is the difference between Shell (orbit) , Subshell and orbital ?
  
• How do you calculate the second ionization energy of Helium?
  
• What is the osmotic pressure in #"mm Hg"# of a solution of #"45.0 g"# ribose dissolved into #"800.0 g"# of water at #40^@"C"#? Assume the density is #"1.00 g/mL"#. #MW = "150.13 g/mol"#
  
• #"AgCl"# has #"pK"_(sp) = 9.744#, #"H"_2"S"# has #"pK"_a = 7.02#, #"HS"^(-)# has #"pK"_a = 13.9#, and #"Ag"("NH"_3)_2^(2+)# has #"pK"_f = -7.22#. Find the solubility of #"Ag"_2"S"# in water, #"0.1 M NH"_3#, and #"0.1 M HCl"#?
  
• How do you write the molecular, complete ionic, and net ionic equation for lithium sulfide reacting with calcium hydroxide? Assume that at the concentrations chosen, calcium hydroxide is soluble.
  
• If a gas in a balloon starts at #"2.95 atm"#, #"7.456 L"#, and #"379 K"#, what is the final pressure in #"torr"# for the gas when it compresses to #"4.782 L"# and #"212 K"#?
  
• How many protons are in lithium atom?
  
• How does an antibonding orbital differ from a bonding orbital? How do they relate to bond order?
  
• What is the electron configuration of nitrogen monoxide?
  
• Covalent bonds are directional in nature. Explain?
  
• What is the wavelength of light that causes an electronic transition for #"Li"^(2+)# if #n_f - n_i = 2# and #n_i + n_f = 4#?
  
• What volume of hydrogen gas is produced when #"6 g"# of magnesium reacts?
  
• Question #18492
  
• How do you get that the ideal gas molar volume is #"22.4 L"#???
  
• The Ka value of a weak acid, HA, is 10-6. An initial solution containing 1.0 M of HA is prepared. What is the pH of the final solution at equilibrium?
  
• What is the bond order of #"H"_2^+#?
  
• Do electron clouds overlap when hybridization occurs?
  
• Calculate the change in entropy when #"1 mol"# of argon gas is heated from #"300 K"# to #"1200 K"#, assuming that #C_P = "20.8 J/mol"cdot"K"# and is constant in the temperature range?
  
• What is the difference between localized and delocalized electron density?
  
• What is the equation that connects pH and its effect on electric potential of an electrochemical cell?
  
• How are microstates formed in chemistry?
  
• Given the following data, how do I find the mols at equilibrium for this reaction?
  
• A box with an initial speed of #2 m/s# is moving up a ramp. The ramp has a kinetic friction coefficient of #3/2 # and an incline of #(2 pi )/3 #. How far along the ramp will the box go?
  
• Calculate the volume of a solid whose base is the ellipse # 4x^2 + y^2 = 4 # and has vertical cross sections that are square?
  
• What kinds of bonds does the #d_(x^2-y^2)# orbital form in transition metal complexes?
  
• What will be the uncertainty in momentum if we know the position certainly?
  
• What are [computer] keyboards made of? As in materials used in keys or the board itself. Thanks!
  
• How many isomers do molecules a) and b) have and can they be dissolved in acid enviroment?
  
• Calculate the change in pH for a buffer solution with an initial pH of #3.9# after addition of #"0.1 M HCl"#?
  
• What is meant by "charge imbalance?"
  
• What is the solubility of #KCl# at 25°C?
  
• How much energy is involved in ionizing hydrogen atom at #n = 1# to #3#?
  
• Why does fluid with high viscosity have strong attractive forces and greater internal friction?
  
• What are all the Lewis symbols for Cl?
  
• Question #edbe0
  
• How to decide which hydrogen would be the leaving group in compounds such as bicyclo[3.3.1]nonane?More specifically why does the bromine substitution occur at the hydrogen attached to the bridgehead and not the other hydrogens attached to the carbons .
  
• Describe the difference between concentrated and dilute at the molecular level??
  
• Verify that #f(x)# is differentiable at #x = 0#? #f(x) = x((e^(1//x) - 1)/(e^(1//x) + 1))#
  
• A certain reaction follows zero-order kinetics. Suppose the reaction went to #50%# completion after #10# minutes. What percentage of completion does the reaction reach in an additional #5# minutes?
  
• 5.25 calories are absorbed by an iron nail. How many joules is this?
  
• What is the mass of 500 molecules of #"NaCl"#?
  
• Is sodium chloride a mixture?
  
• What is the mass of 1.0 mole sample of krypton gas?
  
• Question #1740d
  
• What is the product of adding KOH and Mg(OH)2 to these molecules?
  
• Which of these 4 molecules are chiral molecules and chiral centers?
  
• Absolute zero is what temperature on the Celsius and Fahrenheit scales?
  
• What is the surface area produced by rotating #f(x)=1/(x^2+1), x in [0,3]# around the x-axis?
  
• Why are the bond angles of #"SF"_4# less than predicted by VSEPR theory for a trigonal bipyramidal geometry?
  
• When ammonium chloride dissolved in water the temperature decreases. The energy change for the dissolution of ammonium chloride is #+284Jg^-1# ?
  
• What are the oxidation states of carbon in cyanide and isocyanide?
  
• Question #5b826
  
• What are examples of heterolytic and homolytic cleavage? Could the former happen with methane?
  
• How many #d# orbitals are there?
  
• Which of the following has an octahedral electron geometry? #(A)# #"ICl"_2^+#, #(B)# #"ICl"_2^-#, #(C)# #"IF"_7#, #(D)# #"ICl"_4^-#
  
• What is the #DeltaH_(rxn)^@# for the following reaction if 70.4 kJ of energy is absorbed when 28.2L of NO (g) is produced at STP? #2 NO_2 (g) -> 2 NO (g) + O_2 (g)#
  
• What is an excited state of scandium?
  
• If one has #4.50 xx 10^22# atoms of silver, what mass is available?
  
• The standard enthalpy of reaction, #DeltaH^@"_(rxn)#, for the reaction #NH_3(g) + HCl(g) -> NH_4Cl(s)# is -39.65 kJ. How do you determine the value of #DeltaE^@"_(rxn)# for this reaction at 298 K?
  
• Is there a difference in the dipole moment of a gas molecule in isolation compared to being dissolved in a solvent?
  
• What is the #K_b# for #HSO_4^(-)# if its #K_a# is #1.99#?
  
• What is the equilibrium concentration of #"OH"^(-)# in a #"0.120 M"# solution of #"Na"_2"CO"_3#?
  
• What is the phase diagram for water?
  
• How do you know what the maximum bond angle is for a molecule?
  
• How are Van der Waals forces and ionic bonds similar?
  
• How would I know the enthalpy of formation of barium carbonate on an exam?
  
• What is the density of water vapor at 25 C?
  
• What is the heat flow involved for #"250 mL"# of water that freezes? #DeltaH_f = "6.02 kJ/mol"#. Assume the density of water is #"1.00 g/mL"# at this temperature.
  
• Why entropy is not zero while free energy of formation of element in its standard form is zero?
  
• The two isotopes of uranium, #""^238 U# and #""^235 U#, can be separated by effusion of the corresponding #UF_6# gases. What is the ratio (in the form of a decimal) of the RMS speed of #""^238 UF_6# to that of #""^235 UF_6# at constant temperature?
  
• How would you calculate the enthalpy change, delta H, for the process in which 33.3 g of water is converted from liquid at 4.6 C to vapor at 25.0 C? For water: H = 44.0 kJ/mol at 25.0 C and s = 4.18J/g C for H2O(l).
  
• If we assume that the definition of the inner product of the normalized vectors #hatu_1# and #hatu_2# is #2u_1^2 + u_2^2# (these are vector components), how do you use the Gram-Schmidt process to generate orthonormal vectors from #vecv_1# and #vecv_2#?
  
• For the reaction of #"Au"^(3+)# with #"Cl"_2#, if #["Cl"^(-)]# and #["Au"^(3+)]# were initially #"0.10 M"# and #"0.25 M"# respectively, while #P_("Cl"_2) = "0.5 bar"# initially, what is #E_(cell)#?
  
• What is the only quantum number that does not derive from the Schrodinger equation?
  
• #2"Al"+3"S"→"Al"_2"S"_3# 125g of Al2S3 was produced from 75g of Al & an excess of S What is the theoretical yield of Al2S3?
  
• How many sets of quantum numbers specify all the #2p# orbitals?
  
• Can activation energy ever be negative in ordinary scenarios?
  
• If a buffer contains #"0.110 M"# weak base and #"0.440 M"# of the weak conjugate acid, what is the #"pH"#? The #"pK"_b# is #4.96#.
  
• How do you measure Gibbs free energy?
  
• What new temperature will a gas have if its speed has to become doubled compared to #127^@ "C"#?
  
• For a certain gas in a closed container, the pressure has been raised by #0.4%#, and the temperature was raised by #"1 K"#. What temperature did the gas start at?
  
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