Answers created by Truong-Son N.

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• If the volume of #"2.05 g"# of gas is #"2.55 L"# at #65^@ "C"# and #"1 atm"#, what is its molar mass, assuming it is an ideal gas?
  
• How do you find the total number of electrons allowed in the #n = 3# energy level?
  
• Compound with no sigma bond?
  
• How do you calculate the change in entropy due to heat flow at a constant temperature?
  
• When calcium carbonate is reacted with hydrochloric acid, a certain amount of #"CO"_2# evolves. If #"0.250 mols"# of #"CaCO"_3# was reacted, what volume of #"CO"_2# evolves at 100% yield?
  
• When a certain amount of benzene and toluene are mixed, the total vapor pressure above the solution is #"760 torr"#. Assuming an ideal solution is formed, and knowing the pure vapor pressures, what is the mol fraction of benzene in the solution phase?
  
• Chemistry question? For the hydrogen atom, list the following orbitals in order of increasing energy: 4f, 6s, 3d, 1s, 2p.
  
• What are the partial pressures in #"bar"# if #"70.6 g"# of #"O"_2# is mixed with #"167.5 g"# of #"Ne"#?
  
• What is the equilibrium concentration of #"Al"^(3+)# for the complexation with six equivalents of #"F"^(-)# to form #"AlF"_6^(3-)# if the initial concentrations are #"0.013 M Al"^(3+)# and #"0.104 M F"^(-)#? #K_f = 7.0 xx 10^19#
  
• Write the general chemical equation for this equation ?
  
• How to derive equation for density of ideal gas?
  
• Why is it easier to oxidise #Fe^(2+)# to #Fe^(3+)# than it is to oxidise #Mn^(2+)# to #Mn^(3+)#?
  
• Question #f17d6
  
• Will a gas sample have a root-mean-square speed of #v_(RMS) = sqrt((3RT)/m)#?
  
• Answer these questions about glycine?
  
• Given the following molar absorptivities of amino acids in #"0.1 M"# phosphate buffer at #"pH 7"#, find the ratio of the absorbance at #"260 nm"# over #"280 nm"#, the #A260:A280# ratio, for a mixture of #"2 mol"# of #"Trp"# and #"1 mol"# of #"Tyr"#?
  
• Question #0e77c
  
• What is the formula of cuprous iodide? I have read Cu I and Cu2Cl2 both. Please remove the confusion.
  
• #"500.0 mL"# of solution contains #0.750# millimoles of #"Co"("NO"_3)_2#, #125.0# millimoles of #"NH"_3#, and #100.0# millimoles of ethylenediamine. What is the equilibrium concentration of #"Co"^(2+)# for this complexation reaction?
  
• Ionic equilibrium problem...?proof needed....
  
• What is #["Ni"^(2+)]# at equilibrium upon formation of #"Ni"("NH"_3)_6^(2+)# from #"1 mmol"# of #"Ni"^(2+)# in #"230.0 mL"# aqueous solution containing #"0.300 M NH"_3#?
  
• Why do we write the activity of solids and pure liquids in equilibrium constants at standard conditions as #1#?
  
• If the vapor pressure at the normal boiling point of an aqueous ideal binary mixture is 740 torr, what is the mol fraction of the nonvolatile solute that was dissolved within it?
  
• Question #6cd21
  
• If a proton has a speed of #(5.30 pm 0.01) xx 10^4 "m/s"#, what is the uncertainty in position?
  
• Calculate the enthalpy when 850.0g of ice melts ΔH_fusion for ice=6009.5 J/mol?
  
• What are the assumptions of the kinetic theory of gases, and does it still account for conservation of energy? Shouldn't the system energy decrease eventually?
  
• Question #1571e
  
• By what factor is the ionization energy of hydrogen-like helium greater than that of hydrogen?
  
• Why is the singlet state higher in energy than the corresponding triplet state?
  
• Assuming a homogeneous gas in the context of Kinetic Molecular Theory of gases, how does the root-mean-squared velocity relate to the average gas velocity in one dimension?
  
• What is the enthalpy of reaction at #"373 K"# if the heat capacities are the same at #"273 K"# and we know #DeltaH_(rxn)# at #"273 K"#?
  
• What is the major factor that accounts for most of the difference in these two values of pressure (ideal gas law vs. van der Waals equation)?
  
• Question #9ca84
  
• Is this how #"CHCl"_2^(+)# acts as an electrophile in the electrophilic aromatic substitution? I feel like I have my mechanism arrows in the wrong direction but I don't know how they should go.
  
• Based on quantum number restrictions in atoms, what are...?
  
• If I want the change in Gibbs's free energy for the reverse reaction, do I also take the reciprocal?
  
• Identify the following compounds as strongly acidic, weakly acidic, weakly basic, strongly basic, or pH-neutral in water at #25^@ "C"#? #"Al"("NO"_3)_3#, #"C"_2"H"_5"NH"_3"NO"_3#, #"NaClO"#, #"KCl"#, #"C"_2"H"_5"NH"_3"CN"#
  
• Why is it ok to wash the sides of a flask with DI water during titration even though you are diluting the acid present?
  
• Do electrons really spin like a top?
  
• What is #K_c# if #40%# of #"PCl"_5(g)# is not dissociated?
  
• Which forms the stronger bond with a metal, #"Cl"^(-)# or #"NH"_3#?
  
• What words describe water?
  
• What are the products of the following reactions????
  
• Question #e49bd
  
• When #"0.182 M"# of #"NaF"# (whose conjugate acid, #"HF"#, has #K_a = 6.76 xx 10^(-4)#) associates in water, what is the #"pH"#?
  
• Is #"V"("CN")_6^(3-)# diamagnetic or paramagnetic?
  
• Question #7b3e0
  
• The stratospheric ozone (O3) layer helps to protect us from harmful ultraviolet radiation. It does so by absorbing ultraviolet light and falling apart into an O2 molecule and an oxygen atom, a process known as photodissociation. O3(g)→O2(g)+O(g)?
  
• What is the probability that an electron energy state in #"Ge"# will be occupied at temperature #"Τ = 300 Κ"# if the energy state is greater than the Fermi energy by #"2 eV"#?
  
• The vapour pressure of a dilute aqueous solution of Glucose is 750mm of mercury at 373K. The mole fraction of solute is?
  
• What is the temperature of the gas in Kelvins and Celsius?
  
• What is the electron configuration of mercury?
  
• For the incomplete combustion reaction #"C"_6"H"_6(l) + 3/2"O"_2(g) -> 6"C"(s) + 3"H"_2"O"(l)#, answer these questions about enthalpy?
  
• [Co(H2O)6] [Ag(CN)2]3 , what its name according IUPAC?
  
• How can you derive the ideal gas law?
  
• Could someone please explain to me what does it mean when an atom gets 'excited' and how they reach that state?
  
• What are formation reactions? Use methane as an example.
  
• Why is #"H"_2# not very soluble in water?
  
• How many #"kJ"# are needed to ionize #"100 gram atoms"# of dihydrogen if the ionization energy of hydrogen is #"1312 kJ/mol"#?
  
• What mass of copper is generated by electroplating as much copper as possible using #"96500 C"# of charge?
  
• Which of the following compound names correctly matches up with its chemical formula?
  
• What are term symbols? What should I know about ground-state atomic term symbols?
  
• [Cr (en)2 (H2O) Cl] SO4 .What is its name?
  
• Can Sodium Benzoate and Citric Acid form Benzene and under what conditions?
  
• Why do we know the position of the nucleus well compared to that of an electron?
  
• Question #4c4c7
  
• What shape is specified if the angular momentum quantum number #l = 6#? How many of these orbitals are in this subshell?
  
• What is the electron configuration of tungsten?
  
• If #DeltaH_"fus" = 7.25# and #DeltaS_"fus" = 0.007# for calcium chloride, at what temperature does this substance freeze in a phase equilibrium?
  
• Why are "s" + "p" overlaps directional bonds?
  
• What is the displacement for a particle that starts at #"3.89 m/s"#, and has a constant acceleration of #"3.55 m/s"^2# for #"4.5 s"#?
  
• If a particle accelerates from #"6.9 m/s"# at a rate of #"0.62 m/s"^2# over a time span of #"3.4 s"#, what is the new speed?
  
• Question #d1cdd
  
• What is the integral of #(x^(-4) - sqrt(x^3) + 7)^2#?
  
• Question #0c04e
  
• What is the final temperature of the combined system when #"10.0 g"# of ice is placed into #"50.0 g"# of water at #32.0^@ "C"#? #c_"water" = "4.184 J/g"^@ "C"#, while #DeltaH_(fus)^@ = "333 J/g"# for ice melting into water.
  
• How many molecules(not moles) of NH3 are produced from 4.90*10^-4 g of H2?
  
• Does #"H"_4"O"_2^(+)# exist in water?
  
• Why 3d block transition elements have variable oxidation states???
  
• Which one of the following Lewis structures is definitely incorrect?
  
• For the conversion of glucose to G6P, what is #DeltaG_(rxn)^@#?
  
• For the reaction of #"2.00 L"# of #"0.500 M"# potassium permanganate with #"100.0 g"# of iron solid in the presence of #"1.025 M HCl"#, what volume of #"HCl"# is needed?
  
• How do I make a sine waveform continuous graph of the energy levels of sodium atom against the radial distance from the nucleus?
  
• According to scientists, the mercury concentration in some tuna is #"1.4 ppm"#. How many mercury atoms would be found in #"100 g"# of this tuna?
  
• Why Chromium has [Ar] 3d5 4s1 and Copper has [Ar] 3d10 4s1?
  
• Find #q#, #w#, #DeltaU#, #DeltaH#, and #DeltaS_(sys)#, #DeltaS_(surr)#, and #DeltaS_(t ot)# for #"1 mol"# of an ideal gas undergoing the following changes? The starting pressure is #"3.00 atm"# and ending pressure is #"1.00 atm"# at #27^@ "C"#.
  
• Question #ec81b
  
• Question #8f19d
  
• Does ammonia have filled #pi# orbitals if it doesn't have any #pi# bonds?
  
• What is the thermal energy in #"kJ"# required to melt #"10.234 mols"# of ice?
  
• The volume is 1.5 cm^3 and the mass is 7.5 grams. What is the density?
  
• Can activation energy be negative?
  
• Suppose that samples of methanol and water are mixed so that the mol fraction of methanol is #0.260#, and that the total mass is #"67.0 g"#. From this, determine the mass of water and of methanol that were mixed?
  
• In a closed container at constant pressure, #"N"_2# gas expands from #"49884 cm"^3# to #"62355 cm"^3# when heated to #"395 K"# from an initial temperature. Given that #C_P = "1.014 kJ/kg"cdot"K"#, what is the change in enthalpy for this heating process?
  
• What are the partial pressures of methane and argon in a mixture containing #"2.20 g"# methane and #"7.48 g"# argon if the total pressure is #"988 mm Hg"#?
  
• The de - Broglie wavelength of a neutron at #27^@C# is #lambda#. What will be its wavelength at #927^@C# ??
  
• Why are #pi# orbitals doubly-degenerate?
  
• What are the mathematical formulations of quantum mechanics?
  
• Definition of Quantum Number?? Thank you.
  
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