Unit 3 Test--Lights, Camera, Action . . . All About Chemical Reactions

Multiple Choice (Choose the best answer.)

  1. When the equation ? Fe + ? O2 ? Fe2O3 is balanced, the coefficients of the respective reactants and products (in order) could be:

    2, 3, 2

    4,3,4

    4,3/2,2

    4,3,2

    None of These

  2. The equation H3PO4 + 3 KOH K3PO4 + 3 H2O is an example of which reaction?

    double-replacement

    combination

    decomposition

    single-replacement

    combustion

  3. Which of these expressions is an incorrect interpretation of the balanced equation?


    2 B (s) + 3 O2 (g) 2 BO3 (g)

    2 atoms B + 3 molecules O2 2 molecules BO3

    2 g B + 3 g O2 2 g BO3

    2 mol B + 3 mol O2 2 mol BO3

    All of the above are correct.

    All of the above are incorrect.

  4. In the chemical reaction, A + B C + D, 4 grams of A reacts completely with 3 grams of B to make 2 grams of C. How many grams of D are produced?

    5 g

    9 g

    6 g

    3 g

    4 g

  5. Given the balanced equation:

    16 HCl + 2 KMnO4 2 KCl + 2 MnCl2 + 5 Cl2 + 8 H2O

    If 1.0 mol of KMnO4 reacts, how many moles of H2O are produced?

    0.50 mol

    2.0 mol

    4.0 mol

    8.0 mol

    None of These

    Questions 6 & 7 refer to the equation: 2 NCl3 N2 + 3 Cl2 + 109 Kcal

  6. The reaction shown above is _____.

    an endothermic single replacement reaction

    an endothermic combustion reaction

    an exothermic combination reaction

    an exothermic decomposition reaction

    none of these

  7. 4.00 mol of NCl3 will result in the production of how much energy?

    55.0 Kcal

    109 Kcal

    536 Kcal

    1070 Kcal

    None of These

  8. If CuO + H2 Cu + H2O, how many moles of H2O are produced when 240 grams of CuO react? (Cu = 63.5, O = 16.00, and H = 1.00)

    1.0 mol

    3.0 mol

    18 mol

    54 mol

    None of These

  9. In the reaction 2 Na + H2SO4 Na2SO4 + H2, how many grams of Na are required to produce 1.0 gram of H2? (Na = 23.00, and H = 1.00)

    2.0 g

    11.5 g

    23 g

    46 g

    None of These

  10. If 18 grams of carbon react with oxygen gas to produce carbon dioxide gas, how many molecules of oxygen would be required?

    1.5 molecules

    48 molecules

    9.0 x 1023 molecules

    3.2 x 1024 molecules

    None of These

Problem Solving (Show All Work. Use Correct Units And Significant Figures.)

1) "Flicking your bic" results in the combustion of butane (C4H10). Combustion of hydrocarbons refers to a reaction with oxygen gas to produce carbon dioxide and water. Write a balanced equation for the reaction.



2) Below is data similar to that collected in the Formula of a Hydrate lab. CuSO4* ? H2O is the hydrate. The molecular weight for the anhydrous salt, CuSO4, is 159.5 g/mol.

 

Mass of Crucible and Cover 20.00 g
Mass of Crucible, Cover, and Hydrate 25.00 g
Mass of Crucible, Cover, and Contents after 1st Heating 23.50 g
Mass of Crucible, Cover, and Contents after 2nd Heating 23.20 g

 

 

 

 

a) Calculate the number of moles of anhydrous (dried) CuSO4.


b) Calculate the number of moles of water evaporated.


c) Calculate the ratio of moles of water evaporated to moles of anhydrous CuSO4.


d) What is the formula of the hydrate?

 

3) Nitrogen gas reacts with hydrogen gas to form ammonia gas:

N2 + 3 H2 2 NH3

If 0.50 moles of N2 are available to react with 2 moles of H2.

a) Which reactant will be limiting?

b) How many grams of NH3 will be produced?

c) How many grams of N2 or H2 will remain?

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