Questions asked by rose

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• How many moles of potassium chloride, KCl, are needed to make 100.0 mL of a 2.0 M KCl solution?
  
• If 2.0 mol of propane are burned (reacted with oxygen), how many moles of carbon dioxide will be produced?
  
• P4(s)+6Cl2(g)→4PCl3(l) A reaction mixture initially contains 45.13 g P4 and 132.0 g Cl2.Once the reaction has occurred as completely as possible, what mass (in g) of the excess reactant is left?
  
• Each of the following reactions shows a solute dissolved in water. Classify each solute as a strong electrolyte, a weak electrolyte, or a nonelectrolyte?
  
• Which statement below concerning molecular, complete ionic, and net ionic equations, is true?
  
• Which of the following pairs of aqueous solutions will form a precipitate when mixed?
  
• Which element is oxidized in this reaction? 2CuO+C→2Cu+CO2 Which element is reduced in this reaction? 16H++2Cr2O72−+C2H5OH→4Cr3++11H2O+2CO2
  
• What is the concentration of the unknown H3PO4 solution? The neutralization reaction is H3PO4(aq)+3NaOH(aq)→3H2O(l)+Na3PO4(aq)
  
• How many nitrate ions, NO3-, and how many oxygen atoms are present in 1.00 microgram of magnesium nitrate, Mg (NO3)2? Also what mass of oxygen is present in 1.00 microgram of magnesium nitrate?
  
• For the following reaction, what is the maximum mass of #"HCl"# that can be obtained by the reaction #"37.5 g"# #"BCl"_3# and #"60.0 g"# of #"H"_2"O"#?
  
• How many nitrate ions, #"NO"_3^(-)#, and how many oxygen atoms are present in #1.00# #mu"g"# of magnesium nitrate, #"Mg" ("NO"_3)_2#?
  
• In the industrial preparation of silicon, 188.5 kg of molten SiO2 reacts with 87.3 kg of carbon to produce 78.4 kg of silicon, according to the following balanced equation what is the percent yield of the reaction? SiO2 (l) + 2C (s) ----> Si (l) + 2CO (g)
  
• A 10.000g sample of a compound of nitrogen and oxygen contains 3.686 g of nitrogen. What is the empirical formula? I'm unsure if it is N2O.
  
• Sodium and chlorine react to form sodium chloride: 2Na (s) + Cl2 (g) ----> 2NaCl (s) For the reaction of 44.0g Na with 69.9 g Cl2, what is the limiting reactant and what is the theoretical yield of sodium chloride in grams?
  
• Calculate how many moles of NH3 form when 3.55 moles of N2H4 completely react according to the equation: 3N2H4 (l) ---> 4NH3 (g) + N2 (g) ?
  
• Write a balanced equation for the combustion of liquid penetrate C5H12, in which it combines with gaseous oxygen to form gaseous carbon dioxide and gaseous water?
  
• Determine the molarity of a solution formed by dissolving 648 mg of MgCl2 in enough water to yield 150.0 mL of solution?
  
• What volume (in mL) of #".220 M"# ethanol solution contains #2.90 xx 10^-3# #"mol"# ethanol?
  
• Find the number of waters of hydration (x) in this sample of Epsom salts?
  
• Write the conversion factors for each: cm/minute to in/second, km/h^2 to m/second^2, and mm^3 to cm^3?
  
• How many millimeters of .230 M Na2S are needed to react with 30.00 mL of .513 M AgNO3, according to the following balanced equation? Na2S (aq) + 2AgNO3 (aq) ---> 2NaNO3 (aq) + Ag2S (s)
  
• What is the limiting reagent?
  
• What is the molecular, ionic and net ionic equations for solid sodium bicarbonate plus nitric acid?
  
• Draw the Lewis structure for sulfur dioxide, SO2, which does not require expanded octets. Which of the statements below is true for the Lewis structure of the SO2 molecule that obeys the octet rule?
  
• What volume of .150 M potassium iodide solution will completely react with .155 L of .112 M lead (II) nitrate? equation: 2KI (aq) + Pb(NO3)2 (aq) ----> 2KNO3 (aq) + PbI2 (s)
  
• Which choice represents a pair of resonance structures? Note that lone pairs have been omitted for clarity. A. N≡C−Br and C≡N−Br B. N≡C− and N≡C−H C. H−H and Br−Br D. N=N=O and N≡N−O
  
• Consider the following element combinations. Classify the bonds formed between each pair as ionic, polar covalent, or nonpolar covalent qualitatively based solely on each element's position on the periodic table? Do not conduct calculations.
  
• What is the molarity of a NaOH solution if 26.55 ml are needed to titrate a .6939g sample of KHP?
  
• Balance: CuBr2 (aq) + Na3PO4 (aq) And NH4Cl(aq) + Fe(NO3)3 ?
  
• What are the products for this reaction: NaOH + Na2S ?
  
• Find ΔErxn for the reaction in kJ/mol hexane. The heat capacity of the bomb calorimeter, determined in a separate experiment is 5.79 kJ/∘C ?
  
• Identify the oxidizing agent: #2"S"_2"O"_3 ^(2-) + "I"_2 -> "S"_4"O"_6^(2-) + 2"I"^(-)#?
  
• A system absorbs 186 kJ of heat and the surroundings do 120 kJ of work on the system. What is the change in internal energy of the system? Express the internal energy in kilojoules to three significant figures.
  
• Determine the masses of titanium and iodine that react if #1.66xx10^3# #"kJ"# of heat is emitted by the reaction?
  
• How many mmols in NaOH are used? In an experiment, 5mL of 6 M NaOH is used along with 300 ml distilled water. The solution of the NaOH was titrated into a vinegar solution and it was found that 7.92 mL of NaOH was used.
  
• What is the molarity of the acetic acid solution and what is the percentage by mass, of acetic acid in the solution? Assume the density of the solution is 1 g/mL.
  
• What volume (in mL) of .158 M KOH solution is needed to titrate 20.0 mL of .0903 M H2SO4 to the equivalance point?
  
• Calculate the volume of .00500 M solution needed to make 10.00 ml of the following? .00400 M solution .00300 M solution
  
• What is the predominant intermolecular force in the liquid state of each of these compounds: hydrogen fluoride (HF), carbon tetrachloride (CCl4), and dichloromethane (CH2Cl2)? Either Dipole-dipole forces, Hydrogen bonding or Dispersion forces
  
• Which of the following is considered a nonbonding atomic solid? A. Ca B. Ne C. K D. Cu E. I2
  
• Classify each solid as a covalent, ionic, metallic, or molecular solid? Diamond, frozen carbon dioxide, pure sodium, and sodium sulfide
  
• What is the temperature of 0.59 mol of gas at a pressure of 1.5 atm and a volume of 12.9 L ?
  
• What is the partial pressure of the helium gas? Express your answer in millimeters of mercury.
  
• Classify each solid as a covalent, ionic, metallic, or molecular solid? diamond, pure sodium, sodium sulfide, frozen carbon dioxide
  
• You titrated a 25.00 mL solution of .0350 M oxalic acid with a freshly prepared solution of KMnO4. If it took 37.55 mL of this solution, what was the molarity of KMnO4?
  
• How many grams of oxalic acid dihydrate (COOH)2 x 2H2O, is needed to prepare 525 mL of a .570 M solution?
  
• Arrange KBr, CsI and SrS in order of increasing bond order?
  
• Use valence bond theory to write the hybridization and bonding scheme for NCCH3. Sketch the model with the right geometry?
  
• A mixture of .250 moles O2, .297 moles N2, and .134 moles Ar has a total pressure of 1.95 atm. What is the mole fraction of O2 and what is the partial pressure of O2?
  
• A mixture of #"N"_2#, #"O"_2#, and #"Ar"# has mole fractions of #"N"_2 = .780#, #"O"_2 = .210#, and #"Ar" = .010#. What is the partial pressure of #"O"_2# if the total pressure of the mixture is #"750 torr"#?
  
• The dialysis tube contained sucrose, NaCl, and starch and was placed in a beaker containing water and iodine. The bag started off clear then turned purple it also weighted 8.6 g at the beginning and 10 g at the end. Did water enter the dialysis tube?
  
• Why does water form hydrogen bonds?