Question

1. Given the following reaction

    2C₂H₆(l)   +      7 O₂(g)   ®           4CO₂(g)      +        6H₂O(l)

How many moles of water are produced when 4.5 moles of oxygen react?        (Hint: Use slides 5-8)

2. Given:
I₂     +    3 F₂      ®     2 IF₃

How many moles of I₂ are needed to form 3 moles of IF₃?

How many moles of F₂ are needed to form 10 moles of IF₃?

How many moles of I₂ are needed to react with 3.5 moles of F₂?         (Hint : use slides 9-11)

3. Given:

   CH₄ + 2 O₂   ®   CO₂ + 2 H₂O

   If 5.25 g of methane react,

How much O₂ is used?

How much CO₂ and H₂O form?            (Hint: Use slides 13-14)

4. Consider the reaction of aluminum and oxygen:

         4Al(s) + 3O₂(g) ® 2Al₂O₃(s)

     Which is the limiting reactant if we start with 30.0 g Al and 30.0 g O₂?

     What is the Theoretical Yield for the reaction?

     If 25.85 g of Al₂O₃ was collected at the completion of the

     reaction (actual yield), what is the % yield for the reaction?           (Hint: Use 23-30)

5.   6.25 g of gold and 6.25 g of chlorine are sealed in a container and heated until the reaction is        complete. The product is gold(III) chloride.

    Which reactant is the limiting reactant?

    What mass of gold chloride is formed?

    What mass of the reactant in excess remains?           (Hint: Use 23-30)

7. Determine the limiting reactant when a mixture of 5.00 × 10³ g SiO₂ and 5.00 x 10³ g carbon react.     What is the theoretical yield of silicon carbide?                (Hint: Use lecture notes)       

SiO₂(s) + C(s) →    SiC(s) +   CO(g)

8. DDT is an insecticide banned by the U. S. government because of its hazard to fish and birds. It can     be prepared as follows:

   2 C₆H₅Cl     +      C₂HOCl₃         ®       C₁₄H₉Cl₅   +   H₂O

chlorobenzene     chloral                     DDT

If 451 g of chlorobenzene reacts with 368 g of chloral to yield 507 g of DDT, determine which species is the limiting reactant and calculate the theoretical yield and the percentage yield.    (Hint: Use 23-30)

9.   2.516 g of a compound containing carbon, hydrogen and oxygen (C_XH_YO_Z) is subjected to combustion analysis.

The results show that 3.082 g of CO₂ and 2.705 g of H₂O were produced.

What is the empirical formula for the compound?

If the molecular weight of the compound is 160.2 g/mol, what is the molecular formula of the compound?           (Hint: Use slides 52-61)

10. How many grams of calcium carbonate can be consumed by 45.5 mL of 0.125 M H₂SO₄ (aq) ?

11. Assume 0.456 g of KMnO₄ was dissolved in enough water to give 250.0 ml of solution. What is the Molar concentration of KMnO₄?       (Hint: Use slide 70)

12. What volume of 12 M HCl is required to prepare 100.0 mL of 1.0 M HCl?      (Hint: use slide 82)

13. What is the concentration of a solution prepared by diluting 25.0 ml of 14.8 M HNO₃ to a total volume of 1.50 L?     (Hint: Use slide 82)

14. A Student adds a 30.0 mL aliquot of a 0.515 M HCl solution to a 300.0 mL volumetric flask.

She then filled the volumetric flask to the calibration mark with water.

What is the new molarity of the HCl solution?    (Hint: Use slide 81)

15. What volume of 0.600 M HC₂H₃O₂, acetic acid, is required to neutralize 25.0 mL of 0.175 M Ca(OH)₂?

     2 HC₂H₃O₂ + Ca(OH)₂ ® Ca(C₂H₃O₂)₂ + 2H₂O

   What mass of pure acetic acid is required?      (Hint: Use lab. Lecture notes)

16. A Student adds a 40.0 mL aliquot of a 0.82 M HCl solution to a 300.0 mL volumetric flask.

She then filled the volumetric flask to the calibration mark with water.

What is the new molarity of the HCl solution?    (Hint: Use slide 81)

17. 1.42 g of a compound containing carbon, hydrogen and oxygen (C_XH_YO_Z) is subjected to combustion analysis. The results show that 1.95 g of CO₂ and 1.68 g of H₂O were produced.

What is the empirical formula for the compound?

If the molecular weight of the compound is 160 g/mol, what is the molecular formula of the compound? (use slides 51-61)

18. What volume of 15 M HCl is required to prepare 200.0 mL of 2.0 M HCl?      (Hint: use slide 82)

19. What is the concentration of a solution prepared by diluting 50.0 ml of 15 M HNO₃ to a total volume of 2 L?     (Hint: Use slide 82)

20. Define the following:

a. An Aqueous Solution

b. Molarity

c. A limiting reagent

d. Percent yield

e. Spectrophotometry

Answer 1

1. Given the following reaction

    2C2H6(l)   +      7 O2(g)   ®           4CO2(g)      +        6H2O(l)

How many moles of water are produced when 4.5 moles of oxygen react?

by stoichioimetry:

7 mol of O2 --> 6 mol of H2O

then

ratio is 6/7

since 4.5 mol are reacting

4.5*6/7 = 3.8571 mol of H2O are expected

NOTE: Please consider posting multiple questions in different set of Q&A. We are not allowed to answer to multiple questions in a single set of Q&A.