Answers created by Truong-Son N.

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• Define auto redox reaction. Balance the following equation by ion-electron or oxidation number method: #"K"_2"Cr"_2"O"_7(aq) + "FeSO"_4(aq) + "H"_2"SO"_4(aq) -> "K"_2"SO"_4(aq) + "Cr"_2("SO"_4)_3(s) + "Fe"_2("SO"_4)_3(s) + "H"_2"O"(l)#?
  
• Does pH affect Gibbs free energy?
  
• Why is helium not the most electronegative elemnt?
  
• How do you calculate the ionization energy of lithium?
  
• Calculate the amount of energy it will take to change 20.0 Grams of Water from -3 C to changing it all to vapor at sea level? Please help?
  
• How do we consider that a p orbital in benzene consists of 6 electrons?
  
• FRQ - Electrochemistry?
  
• What are the three main types of radioactive decay?
  
• Solution A has a hydronium of 1.3 x 10^-3 M. Solution B has a hydroxide ion concentration of 4.5 x 10^-8M. calculate the ph of solutions A and B. show all calculations?
  
• If it takes #"[HALF of the]"# Iodine-131 approximately 8 days to change to Xenon-131, how many days would have passed if 75% of it has changed to Xenon-131?
  
• Can someone plz tell me what is the answer for this question plz ?
  
• A 25.0 ml sample of 0.150 M nitrous acid is titrated with a0.150 M NaOH solution. What is the pH at the equivalence point? theKa of Nitrous Acid is 4.50 x 10-4.
  
• #beta^-# decay problem?
  
• Determining energy difference (in kJ/mol) between excited and ground states of Li+?
  
• When solid melts...? a)entropy will increase b)entropy will decrease
  
• Is the energy of subshell s bigger than p?
  
• How to determine coordination number in transition metal complexes?
  
• For first-row transition metals, why do the 4s orbitals fill up before the 3d orbitals? And why are electrons lost from 4s orbitals before 3d orbitals?
  
• Which energy change corresponds to the enthalpy change of atomization of #H_2# at 298 K ?
  
• How long can these people remain in class if the body temperature is #37 ^@ C# and a person feels uncomfortable above this temperature?
  
• A 1956 dime is made of a silver-copper alloy and has a mass of 2.490. The dime was dissolved in nitric acid and a blue solution remained. The solution quantitatively transferred to a 100mL volumetric flask and brought to volume with water...?
  
• What is beta minus?
  
• Can entropy change be positive for both a system and its surrounding?
  
• Gravimetric Assignment: Determine the percentage by mass calcium carbonate in the egg shells ????
  
• If combustion reactions are spontaneous, why is there an increase in entropy for the system and surrounding?
  
• What are the pH of the solutions?
  
• Calculate the pKa of hypochlorous acid. The pH of a 0.015 M solution of hypochlorous acid has a pH of 4.64 ?
  
• I know that nitrogen, oxygen, etc. are all diatomic. But when do I know to add the 2 at the end of their formula while writing equations?
  
• The molar solubility of CoCO3 in a (1.00x10^-3) M Na2CO3 solution is {M2} M. What is the Ksp for CoCO3?
  
• What energy change is observed?
  
• A second order reaction is 60% completed in 1 hour. What is the value of the rate constant, if the initial reactant concentration is #[A]_0# #"mol"cdot"L"^(-1)#?
  
• What are the similarities and differences between the lanthanides series and the actinide series?
  
• When #"32.4 mL"# of liquid benzene (#C_6H_6#, #rho = "0.879 g/mL"#) reacts with #"81.6 L"# of oxygen gas, measured at #"1.00 atm"# and #"25°C"#, #1.19xx10^3 "kJ"# of heat is released at const. pressure. What is #DeltaH^@# for the following reaction?
  
• Benzene and toluene form nearly ideal solution.The vapour pressure of pure toluene is 22 torr at 20 degree celcius for equimolar mixture of benzene and toluene at 20 degree celcius the vapour pressure of toluene is.?
  
• How do you calculate the mass defect for C-14? How do you calculate the binding energy?
  
• A 0.4793-g sample of a chlorocarbon compound was analyzed by burning it in oxygen and collecting the evolved gases in a solution of NaOH. After neutralizing, the sample was treated with 40.62 mL of a 0.1619 M AgNO3 solution?
  
• Why is the change in free energy zero when substances are in their elemental state?
  
• What is Nernst equation?
  
• There are seven naturally occurring diatomic molecules. What are they?
  
• Under identical conditions of temperature and pressure, which of the following gasses is the lightest? a) #"Ne"# b) #"O"_2# c) #"Ar"# d) #"H"_2#
  
• Discuss the following structure (η5-C5H5)(PPh3)Ir(η2-NCC6H4Cl). What is somewhat unique about the structure?
  
• Could someone please explain (ii)* to me?
  
• How to draw the potential energy diagram for this reaction?
  
• On combustion, benzoic acid releases 26.38 KJ/g. The bomb calorimeter contained 1.000 g of benzoic acid. The temperature of the calorimeter rises from 24.32 degrees C to 27.05 degrees C?
  
• What is a state function? What are examples of a state function and when its not a state function?
  
• Why does nitrite have a negative charge instead of a positive charge?
  
• What is the pH of #1.0 xx 10^(-10)# #"M HCl"#?
  
• What is the internal energy for an isothermal process?
  
• What is isothermal process?
  
• If the change in free energy of formation is zero, is change in enthalpy of formation always zero as well?
  
• For hydrogen peroxide and chlorine gas that are in the same amount, phase, temperature, and volume, why is it that hydrogen peroxide has greater entropy?
  
• The values of Quantum numbers for the 5th electron of boron and last entering electron of potassium?
  
• Why is acid more affective at changing color than temperature?
  
• A buffer that contains 1.10 mol/L B and 0.700 mol/L BH+ has a pH of 9.65. What is the pH after 0.0045 mol of HCl is added to 0.500 L of this solution?
  
• Is H2, a monoatomic or diatomic gas??
  
• What is the degree of freedom for O2?
  
• Which having higher bond angle and why #"ClO"_2# or #"ClO"_2^-#?
  
• Acid base Equilibrium?
  
• What is the molar enthalpy of fusion of magnesium?
  
• The ease with which the charge distribution in a molecule can be distorted by an external electrical field is called the?
  
• A compound A with a molecular formula C3H8O is oxidised with acidified potassium dichromate(VI) to form a liquid B. B reacts with hydrogen cyanide to form a compound C that contains 3 carbon atoms. What are the structures of A B and C?
  
• What are comparisons between electrons, beta particles, and positrons?
  
• How is absolute zero achieved?
  
• Determine the mass of copper deposited at the cathode by a current of 0.05A flowing through aqueous copper (II) sulphate for 30minutes?
  
• Why can #CO_2# be easily solidified?
  
• What are the different kinds of f orbitals?
  
• Why do solutes lower the freezing point?
  
• How to do 16th question?
  
• Calculate the molar solubility of Zinc II Phosphate(Zn3(PO4)2). Ksp = 9.0e-33. ?
  
• Predict whether the change in entropy, for the following reaction will be positive or negative H2(g) + (1/2) O2(g) → H2O(g) . Why is this positive, even though there are less mols in the product?
  
• Consider an ammonia/ammonium chloride buffer. Kb for ammonia is 1.8 χ 10—5. Select all the correct statements from those listed below?
  
• L=4 subshell??
  
• How to find the pH when adding unknown amounts of weak acid into known amounts of strong base??
  
• Is sand a solid, liquid or gas?
  
• Kindly solve this? which option is correct?
  
• Could someone tell me if I'm right on this one?
  
• Can someone please explain me? I have some questions about the Periodic Table...(sorry for any grammar mistake)
  
• What does a closed shell mean?
  
• Hi, how do I know which is product and which is reactant, when there are just plus signs? Or just arrows?
  
• What does ligand field theory enables us to explain that crystal field theory does not?
  
• Gibbs Free Energy. Why are equilibrium constants for a chemical reaction temperature dependent?
  
• Formic acid (HCOOH), Ka = 1.8 X 10-4, is the irritant associated with ant stings. Calculate the equilibrium concentrations of all species, HA, H+, and A-1, of an aqueous solution containing 18.0 g of formic acid per liter. ?
  
• Calculating Ksp of calcium hydroxide?
  
• In the following reactions, ZnO is respectively acting as a /an ?
  
• What mass of ethylene glycol( non -volatile, non ionizing, 62.1g/mole) is neededto prepare 10.0L water(#rho = "1 g/mL"#) with a freezing point of ( -23 degree celcious) ?
  
• Why "Zn" creates complicated compound, Wheather it is not a transition element?
  
• What volume of 0.20M Ca(OH)2 will neutralize 45.0 mL of a 1M solution of HClO3?
  
• Would someone please help me? When doing isomers of pentene, how do you know that you have 6?
  
• Boric acid is written as H3BO3 or B(OH)3...but if it is written as B(OH)3...why is it still an acid and not a base?
  
• Will someone please help me with this? Thank you so much!!!
  
• What is the pH at the equivalence point of the titration of 30 mL of 0.2 M nitrous acid with 0.1 M NaOH at 25 °C?
  
• Why water is monodentet? Wheather it has two Pairs of lonely electrons?
  
• Please solve this phenol reaction based problem?
  
• What can be the least energy of a system as per Heisenberg's uncertainty principle?
  
• How does volume affect microstates?
  
• How to do 161st question?
  
• How do you find maclaurin series for f(x) = x^2 ln(1 + x^3)?
  
• What is the concentration when equilibrium is reached?
  
• How to draw the Newman projection of ethene down the C=C bond?
  
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