Questions asked by Sydney J

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• Ethyne is completely combusted as per the following equation. If #2.40 xx 10^(-1) # moles of oxygen react, how many moles of carbon dioxide form? (Answer in mol to 3 s.d. in proper scientific notation.)
  
• Water, H2O, is made via its formation reaction. How many moles of water form when (7.69x10^0) moles of oxygen gas react? (Answer in mol to 3 s.d. in proper scientific notation)
  
• When (8.30x10^-1) g of silver nitrate is dissolved in water and then mixed with excess potassium iodide solution (6.0000x10^-1) g of precipitate form. What is the percent yield of the reaction? (Answer to 3 s.d. and in proper scientific notation)
  
• #3.761xx10^1color(white)(.)"L"# of an ideal gas is in a balloon at #1.000xx10^0 color(white)(.)"atm"#. The weather changes, and the volume of the balloon changes to #5.00xx10^1 "L"#. What is the new pressure, assuming no change in temperature?
  
• A sample of gas in a flexible sided container has a volume of (3.100x10^-2) L when the temperature is (3.540x10^2) OC. The temperature is changed to (8.42x10^2)OC. What is the new volume of the gas assuming no change in pressure?
  
• Ammonia is being formed as per: N2(g) + 3 H2(g) --> 2NH3(g) If 0.277 L of nitrogen reacted in full, what volume of ammonia has been generated? (Answer in L to 3 decimal places.)
  
• (8.8400x10^-1) mol of an ideal gas has a pressure of (1.50x10^2) kPa and temperature of (2.5700x10^2) K. What is the volume of the gas?
  
• A weather balloon has a volume of (7.20x10^1) L when at the surface where the pressure is (9.3000x10^1) kPa and a temperature is (2.6000x10^2) K. (see more below)?
  
• (8.000x10^-1) g of a gas is collected in the lab and found to have a volume of (8.9000x10^-1) L when the pressure is (9.600x10^1) kPa and the temperature is (3.00x10^2) K. According to this collected data what is the molar mass of the gas?
  
• Dissolving NaCl in water is likely to be (endo/exo thermic) and the reaction will feel (hot/cold) to the touch? (choose the right answer between the two choices)
  
• What are the products of the dissociation of magnesium iodide? (select all correct answers): ~ 2 I+(aq) ~ Mg2-(aq) ~ I2-(aq) ~ 2 I-(aq) ~ Mg(s) ~ Mg2+(aq)
  
• A student needs to make #5.00xx10^1# mL of a potassium carbonate solution with a concentration of #3.3000xx10^(-2)# mol/L. What mass of potassium carbonate should they use to make the solution? (Answer to 3 s.d. in g)
  
• Which are the spectator ions when a solution of copper(II) nitrate reacts with a solution of potassium hydroxide?
  
• A bottle of calcium bromide contains a bromide ion concentration of 0.10 mol/L. What is the concentration of the calcium bromide?
  
• What is the concentration of sodium ions in a (2.2x10^0) mol/L solution of sodium carbonate? (answer to 2 s.d. in mol/L}
  
• A solution has a pOH of 6.39. What is the solutions pH? (You must answer to the correct number of s.d.'s)
  
• A solution of potassium fluoride turns litmus paper blue. What are the products of the modified Arrhenius net ionic equation for this compound? Question options: #~H_2O# #~F^-# #~HF# #~H_3O^+# #~HKF^+# #~OH^-#
  
• What is the concentration of a lithium hydroxide solution that has a pOH of (3.1x10^0)? (answer to 2 s.d. in mol/L)
  
• What is the pH of a 6.2 x 10-2 mol/L solution of nitric acid?
  
• 20.000 mL aliquots of a phosphoric acid solution with an unknown concentration is titrated with some 0.624 mol/L sodium hydroxide solution.The average volume of the sodium hydroxide added was 24.01 mL. What is the concentration of the phosphoric acid?
  
• A solution of sodium hydroxide has a concentration of (2.1 x 10^-1)mol/L. What colour does the solution turn when a few drops of indigo carmine are added?
  
• What type(s) of intermolecular bonding do each of the structures contain? Do all Isomers have the same melting point/boiling point? Why or why not?
  
• What physical property of hydrocarbons is used for fractionation?
  
• What kind of polymer is polyvinyl alcohol? How do you know?
  
• How do the physical properties of soap allow water to be used to clean grease??
  
• The equilibrium constant for the reaction H2+I2<->2HI is 54.8 at 425°. What are the concentrations for all gases present if there is 1.000mol of each gas in a one litre container?
  
• The equilibrium constant for the reaction 2IBr<->I2+Br2 is 8.5×10^-3 at 150°C. If 0.0300 mol of IBr is introduced to a 1L container, what is the concentration of the substance after equilibrium is established?
  
• At 500K, NOCl is 90% decomposed for the reaction 2NOCl<->2NO+Cl2. If we assume that 1.00mol of NOCl in 1.00L before dissociation, what is the value of Kc for equilibrium at 500K?
  
• A mixture of 1.000mol of CO and 1.000mol of H2O is put in a 10.00L container at 800K, at equilibrium, 0.665mol of CO2, and 0.665mol of H2 are present. The equation: CO+H2O<->CO2+H2. What are the equilibrium concentrations of all 4 gases?
  
• What is the concentration of Cr2O7 in mol/L?