Ch (2) : Calculations With Chemical Formulas And Equations

15 Questions | Total Attempts: 227

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Ch (2) : Calculations With Chemical Formulas And Equations

QUIZ FOR (( calculations with chemical formulas and equations )) Faculty of Engineering, Zagazig University BY &


Questions and Answers
  • 1. 
    Percentage of Magnesium [Mg] in Magnesium sulfate [MgSO4] Given Atomic Weights:  Mg = 24  .   S = 32   .  O = 16  
    • A. 

      40

    • B. 

      20

    • C. 

      12

    • D. 

      60

  • 2. 
    Balance the following equation: Mg3N2 + H2O  Mg(OH)2 + NH3
    • A. 

      Mg3N2 + 6H2O --> 3Mg(OH)2 + 2NH3

    • B. 

      Mg3N2 + 6H2O --> 3Mg(OH)2 + NH3

    • C. 

      Mg3N2 + 2H2O --> Mg(OH)2 + NH3

    • D. 

      Mg3N2 + 3H2O --> 3Mg(OH)2 + 2NH3

  • 3. 
    Calculate the mass % of carbon in carbon monoxide.
  • 4. 
    A reaction that produces crude iron from iron ore is shown below: Fe2O3 (s) + 3CO (g 2Fe (s) + 3CO2 (g) How many moles of iron could be produced from the reaction of 10 mol Fe2O3 and 25 mol of CO?   
    • A. 

      10 mol

    • B. 

      25 mol

    • C. 

      17 mol

    • D. 

      20 mol

    • E. 

      35 mol

  • 5. 
    You are given the following percentages: 40.05% S and 59.95% O. Find the empirical formula for these elements
    • A. 

      SO

    • B. 

      SO2

    • C. 

      SO4

    • D. 

      SO3

  • 6. 
    Given the following: 42.07% Na, 18.89% P, and 39.04% O, determine the empirical formula
    • A. 

      NaPO2

    • B. 

      Na2PO3

    • C. 

      Na3PO4

    • D. 

      NaPO4

  • 7. 
    Styrene has the empirical formula CH, and there is 92.25% carbon and 7.75% hydrogen. If you have a molar mass of 104g/mol, what is the multiplier or factor to get the molecular formula?
    • A. 

      6

    • B. 

      2

    • C. 

      4

    • D. 

      8

  • 8. 
    Al(OH)3 + 3HCl --> 3H2O + AlCl3 If you have 14.0 grams of aluminum hydroxide, how much aluminum chloride is produced?
    • A. 

      14.0 g

    • B. 

      17.9 g

    • C. 

      23.9 g

  • 9. 
    Al(OH)3 + 3HCl --> 3H2O + AlCl3 If you actually recovered 22.0 grams of aluminum chloride, what is the percent yield of the reaction?
    • A. 

      100%

    • B. 

      92%

    • C. 

      69%

  • 10. 
    What is the percentage of oxygen in carbon dioxide? (CO2)
  • 11. 
    Empirical Formula: 39.8% K, 27.8% Mn, 32.5% O
    • A. 

      N3,Mn,5O

    • B. 

      K2,Mn,O4

    • C. 

      Mn3,K,O7

    • D. 

      O10,Mn,5K

  • 12. 
    The simplest formula of a substance shows
    • A. 

      the actual number of atoms of each element in one molecule of a substance.

    • B. 

      the elements that make up one molecule of the substance and the simplest whole number ratio between the atoms.

    • C. 

      the number of molecules in a sample of the substance.

    • D. 

      the molecular mass of the substance.

  • 13. 
     A compound is found to have a molecular mass of 90 atomic mass units and simplest formula of C2H5O. The molecular formula of the substance is: (Atomic mass of C = 12 amu, H = 1 amu, O = 16 amu)
    • A. 

      C3H6O3

    • B. 

      C4H26O

    • C. 

      C4H10O2

    • D. 

      C5H14O

  • 14. 
    How many grams of oxygen are in one mole of calcium carbonate, CaCO3? (Atomic mass of O = 16 amu.)
    • A. 

      16 grams

    • B. 

      32 grams

    • C. 

      48 grams

    • D. 

      64 grams

  • 15. 
    The ionic compound containing Fe3+ and SO42- would have the formula
    • A. 

      FeSO4

    • B. 

      Fe2SO4

    • C. 

      Fe2(SO4)3

    • D. 

      Fe3(SO4)2

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