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Category: Homework
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Experience:  BSc(Hons) - 1st class honours in Chemistry, MPhil (Chemistry), MBBS (Medicine)
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1. The number of moles of F in 27 g of OF2 is __________. (Points

Resolved Question:

1. The number of moles of F in 27 g of OF2 is __________. (Points: 4)
        13 moles
        6.4 moles
        0.40 moles
        0.20 moles
        1.0 moles


2. Automotive batteries generally are filled with sulfuric acid. If a battery has a volume of 1.78 L and contains 3.28 x 103 grams of sulfuric acid, what is the density of sulfuric acid in g/mL? (Points: 4)
        5.43 x 10-4 g/mL
        5.84 x 103 g/mL
        1.84 g/mL
        19.85 g/mL


3. Which of the following element/chemical symbol pairs is incorrectly matched? (Points: 4)
        Chromium: Cr
        Rubidium: Rb
        Scandium: S
        Argon: Ar
        Gold: Au


4. Which of the following pairs of atoms contain the same number of neutrons? (Points: 4)
        27Al and 31P
        9Be and 7Li
        22Ne and 23Na
        58Ni and 58Fe


5. Which of the following statements is incorrect? (Points: 4)
        All atoms of an element have the same atomic number.
        All atoms of an element must have the same mass.
        All atoms of an element have the same number of electrons.
        Atoms of an element may have different numbers of neutrons.


6. In the electron configuration of a phosphorus atom, there are __________ valence electrons in the outer shell. (Points: 4)
        zero
        five
        one
        three
        four


7. Which of the following involves chemistry? (Points: 4)
        automobiles
        detergents
        cooking
        all of the above


8. Which of the following statements about a hypothesis is false? (Points: 4)
        A hypothesis is an all-encompassing scientific explanation.
        The basis of a hypothesis is experimentation and observation.
        A hypothesis can evolve into a theory.
        A hypothesis is a tentative explanation for observations made during an experiment.


9. What is the difference between a homogenous and a heterogeneous mixture? (Points: 4)
        A homogeneous mixture is the same as a heterogeneous mixture except that it is typically at a higher temperature.
        A homogeneous mixture is uniform throughout, while a heterogeneous mixture is not uniform.
        A homogeneous mixture is not uniform throughout, while a heterogeneous mixture is uniform.
        There is no difference between the two mixtures.


10. Tap water consists of water, sodium and chloride ions, and possibly bacteria, chlorine, and other ingredients. Which choice best defines what tap water is? (Points: 4)
        a pure substance
        an element
        a mixture
        a compound


11. Given what you have learned about prefixes, calculate how many liters of liquid are in a container that has 579 mL of the liquid. (Points: 4)
        5.79 L
        0.0579 L
        0.579 L
        57.9 L


12. Which of the following sets of measurements of a dose of cough medicine, all in mL, can be described as precise but not accurate if the true value is 15.4 mL? (Points: 4)
        15.4, 15.5, 15.3
        28.3, 28.2, 28.4
        18.2, 12.7, 16.5
        none of these answers is correct


13. With regard to the proper number of significant digits, which of the following calculations is carried out incorrectly? (Points: 4)
        18.8 ÷ 4.3 = 4.37
        1.99 ÷ 18.77 = 0.106
        2.8437 ÷ 1.9999 = 1.4219
        2.1 ÷ 5.558 = 0.38


14. Suppose a company is going to expand and is considering buying a plot of land in Europe. If they want to have an area of 2.50 square miles, about how much land should they buy, in units of square kilometers, if 1 mile = 1.6093 kilometers? (Points: 4)
        6.47 km2
        4.02 km2
        5.0 km2
        1.6 km2


15. Express the number 0.0000027 in standard exponential form. (Points: 4)
        0.027 × 10-4
        0.27 × 10-3
        2.7 × 106
        2.7 × 10-6
        None of the above


16. Which component of the atom has no charge? (Points: 4)
        electrons
        protons
        neutrons
        all components have a charge


17. The fact that the periodic table is ordered according to atomic number rather than atomic mass suggests that (Points: 4)
        The number of neutrons is the most consistent guide to the characteristics of an element.
        Atomic mass and atomic number are perfectly correlated.
        Mendeleev’s work on the periodic table was misleading.
        Atomic number is XXXXX more consistent guide to the characteristics of an element.


18. C2H2 is a chemical formula for acetylene. Which type of chemical formula is this? (Points: 4)
        A molecular formula
        An empirical formula
        A structural formula


19. Titanium will form the cation Ti4+. What is the formula for the ionic compound titanium(IV) oxide, the white pigment in paint? (Points: 4)
        TiO4
        Ti2O
        TiO2
        TiO


20. Which is the formula for tetraphosphorus hexoxide? (Points: 4)
        P5O6
        P4O6
        P4O5
        P5O7


21. Which of the following equations is balanced for the reaction?
HF + SiO2 --> SiF4 + H2O (Points: 4)
        4HF + SiO2 --> SiF4 + H2O
        8HF + 2SiO2 --> 2SiF4 + 3H2O
        2HF + SiO2 --> SiF4 + H2O
        4HF + SiO2 --> SiF4 + 2H2O


22. Which of the following equations is properly balanced, including having the smallest whole number coefficients? (Points: 4)
        2BaCl2 + 2Na2SO4 --> 2BaSO4 + 4NaCl
        2Na + 4Cl2 --> 2NaCl
        2Na + 2H2O --> 2NaOH + H2
        2HCl + Mg --> 2MgCl2 + H2


23. How many molecules of hydrogen chloride (HCl) are in 0.500 moles? (Points: 4)
        18.06 × 1023 molecules
        6.02 × 1023 molecules
        3.01 × 1023 molecules
        12.0 × 1023 molecules


24. Lucite is 71.4% carbon, 9.59% hydrogen, and 19.01% oxygen. What is the empirical formula for Lucite? (Points: 4)
        C5H8O
        C89HO31
        C7HO2
        The formula cannot be determined with only this information.


25. Which of the following equations accurately represents the calculation needed to determine the number of grams of FeCl3 produced from 4.00 moles of Cl2?

3Cl2(g) + 2FeI2(g) --> 2FeCl3(g) + 2I2(g) (Points: 4)
       
       
       
       


26. How many moles of iodine are produced from 7.00 moles of chlorine, according to the equation shown?
3Cl2(g) + 2FeI2(s) --> 2FeCl3(s) + 2I2(g) (Points: 4)
        4.67 mol
        10.5 mol
        4.4 mol
        1185.25 mol


27. Usng the following balanced chemical equation, determine the limiting reactant in the reaction between 3.0 grams of titanium and 8.0 grams of chlorine gas?

Ti(s) + 2Cl2(g) --> TiCl4(s) (Points: 4)
        Cl2
        TiCl4
        Ti
        In this reaction, there is exactly the stoichiometric amount of each reactant.


28. If 1.22 g of sodium sulfate, Na2SO4 (formula mass = 142.0 g/mol) are dissolved in enough water to make 100.0 mL of total solution, what is the molarity of this solution? (Points: 4)
        0.345 M
        0.0859 M
        0.345 m
        1.22 M


29. Which statement about solutions is not true? (Points: 4)
        A solution is any homogeneous mixture containing two or more substances.
        The two fundamental substances that make up a solution are the solute(s) and solvent.
        The solvent is the component in the majority.
        If the solute doesn't dissolve in the solvent at all, this is a supersaturated solution.


30. A chemist is producing copper(II) chloride using the following reaction:
Cu(s) + Cl2(g) --> CuCl2(s)
In one reaction, the chemist uses 15.0 g of copper metal and 10.0 g of chlorine gas as reactants. When the reaction reaches completion, 16.0 g of copper(II) chloride has been produced. What was the percent yield of the reaction? (Points: 4)
        62.5%
        45.1%
        84.4%
        93.7%
Submitted: 5 years ago.
Category: Homework
Expert:  Susan replied 5 years ago.

Hello!

 

The answers are as follows:

 

  • 1. d
  • 2. c
  • 3. c
  • 4. b
  • 5. b
  • 6. b
  • 7. d
  • 8. a
  • 9. b
  • 10. c
  • 11. c
  • 12. a
  • 13. a
  • 14. a
  • 15. d
  • 16. c
  • 17. d
  • 18. a
  • 19. c
  • 20. b
  • 21. d
  • 22. c
  • 23. c
  • 24. a
  • 25. Options not provided. Given equation is correct.
  • 26. a
  • 27. a
  • 28. b
  • 29. d
  • 30. c

Take Care.

Expert:  David Scrafton replied 5 years ago.
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David Scrafton, Graduate Student
Category: Homework
Satisfied Customers: 111
Experience: BSc(Hons) - 1st class honours in Chemistry, MPhil (Chemistry), MBBS (Medicine)
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