Chemistry 11 Practice Final

 

 

  1. A compound is decomposed to yield 3.33 g of carbon and 8.87 g of oxygen gas.  What is the empirical formula for the compound?  If the molar mass of this compound is known to be 44.0 g/mol find its actual molecular formula.
  2. In the lab you experimented with a reaction involving an iron wire placed in a solution of copper (II) sulfate.  The grade 9s have done a similar experiment this week using steel wool and noted that the test tube containing the reaction got very warm:
    1. Is this reaction endothermic or exothermic?
    2. Sketch an energy diagram representing this reaction. (Label the axes, the activation energy, activated complex and enthalpy.)
    3. List 4 specific ways in which you could speed this reaction up.
    4. Why did the grade 9 version of the experiment have a notable temperature rise while the grade 11 version did not?
  3. Consider the reversible reaction:

           2SO2(g) + O2(g) 1 2SO3(g) + 192.3kJ/mol

How will each of each of the following affect the equilibrium point?:

    1. Increasing the temperature. 
    2. Increasing the pressure.
    3. Increasing the concentration of oxygen.
    4. Increasing the concentration of sulfur trioxide.
    5. Adding a catalyst.
    6. Write an expression for the equilibrium constant.
    7. Is the reaction endothermic or exothermic?
    8. What is the enthalpy for the reaction?
  1. Silver (I) chloride dissolves in water with Ksp = 1.8 x 10-10
    1. Write the dissociation equation for this.
    2. Write the expression for the solubility products constant.
    3. If 100g of silver chloride are dissolved in water to make 100mL of solution what will the concentration of silver and chloride ions be at equilibrium?
  2. In an experiment earlier in the year you added lead (II) nitrate to potassium iodide and a yellow precipitate of lead (II) iodide formed.  Explain why this happened using the idea of the solubility products constant.
  3. If you make 1.50 L of hydrochloric acid (HCl, a strong acid) of concentration 0.550 M:
    1. How many moles of hydrochloric acid do you need?
    2. What will the concentration of hydronium ions be?
    3. What will the concentration of hydroxide ions be?
    4. What will the pOH be?
    5. What will the pH be?
    6. How much of a 0.110 M NaOH solution is required to neutralize it?
  4. Acetic acid (CH3COOH) has an acid dissociation constant of 1.8 x 10-5 .  If a solution is made with 1.0 mole of CH3COOH dissolved in water to make 5.0 liters of solution:
    1. Write the equation for the reaction of the acetic acid and water.  Label the acid, base, conjugate acid and conjugate base.
    2. What will the initial concentration of CH3COOH be?
    3. What will the final pOH be?
    4. What will the concentration of the conjugate base of acetic acid be?
  5. Sketch, give formula and name a straight chain alkane, alkene and alkyne with six carbon atoms.  Then give a branched isomer for each.  Draw 4,5-diethyl 1-octyne.
  6. What is the molar mass of decyne?  Write its balanced combustion reaction.
  7. Three alpha particles can fuse together to make a new single nuclide.
    1. Write the equation for this reaction.
    2. Using the data in the table below calculate the mass defect for the reaction
    3. Is energy absorbed or given off in the reaction?
    4. How much energy?
  8. For bismuth-214:
    1. Write the full symbol
    2. How many protons does it have?
    3. How many neutrons does it have?
    4. How many electrons will an ion with +1 charge have?
    5. What is the atomic mass number?
    6. Write an equation for this element undergoing b-decay.
    7. Write an equation for this element undergoing a-decay.
    8. Write an equation for this element undergoing g-decay.
  9. Radon-222 undergoes a-decay to Polonium.  The mass of the parent nuclide is 221.9703 amu.  The mass of the daughter nuclide is 217.9628 amu and a helium nucleus has mass 4.0015 amu.  What is the energy released in kJ per mole?
  10. The ½ life of iodine-125 is 60 d.  If a pure sample of iodine-125 is originally 21.0g what will the mass of remaining iodine-125 be after 180d?
  11. Consider the oxidation-reduction reaction:           Na + Cl2(g) 1 Na+ + Cl-
    1. Write the half-reactions.
    2. Which reactants are the oxidizing and reducing agents?
    3. What is the balanced reaction?

 

Data:

 

 

Mass of Helium-4 = 4.0015 g/mol

Mass of Carbon-12 = 12.0000 g/mol

Mass of Oxygen-16 = 15.9998 g/mol

Mass of Oxygen-18 = 17.9997 g/mol

Speed of light in vacuum = 3.0 x 108 m/s

 

 

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