CHM 1045
Dr. Michael Blaber

Name_________________________

SS #__________________________

Exam #1 100 points total

  1. Indicate whether the following are most likely a pure substance, a homogenous mixture or a heterogenous mixture (5 points)

    2. a. A packet of cool aid

    b. A packet of cool aid dissolved in water

    c. A bronze coin

    d. A gold bullion coin

    e. A chocolate chip cookie made with blue M&M’s

     

  2. Indicate whether the following represent physical or chemical changes (5 points)

    3. a. A sugar cube dissolving in hot water

    b. An Alka-Seltzer tablet dissolving in water

    c. The heating of water to produce steam

    e. The burning of candle wax to produce soot

    f. The cooking of eggs to produce an omelet

     

  3. In the following diagram, in which direction would the nucleus of a helium atom be deflected? (the particle is coming directly at you). (5 points)

    4.  

  4. For the following elements, write down the most likely ionic form (5 points)

    5. a. Be

    b. S

    c. P

    d. Li

    e. O  

     

  5. Write the balanced chemical equation for the combustion of pentanol (C5H12O) (5 points)

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  6. Lithium can react with water to produce the Lithium Hydroxide and Hydrogen gas. Write the balanced chemical equation for this reaction and predict all other elements that you would expect to be able to react with water in a similar type of reaction. (10 points)

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  7. What is the percentage by mass of C, H and O in ethanol (C2H6O)? (10 points)

    8.  

     

      

     

     

     

  8. How many grams are there in 1.72 moles of acetone (CH3)2CO ? (10 points)

 

 

 

  1. A certain combustible compound, containing C, H and O atoms, is 53.3% C, 11.2% H and 35.5% O by mass. The experimentally determined molecular mass is 90.14 amu. What is the empirical and chemical formula for this compound? (10 points)

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  2. Heptanol has the formula C7H16O and can be combusted in the presence of oxygen. If 15.0 g of heptanol is combusted in the presence of 23.0 g of O2, how many grams of water will be produced? What is the limiting reagent? (Be sure to show the balanced equation for this reaction). (20 points)

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  3. What is the molarity of a 2.92 liter solution of water containing 27g of of Mg3(PO4)2? (5 points)

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  4. You have a stock solution of 3.0 M MgCl2 and some pure water. How would you use these to produce 0.157 liters of a 0.25 molar solution of MgCl2? (10 points)