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Chemistry

Additional Practice Problems

  1. Describe what is happening between the following points and show what is taking place using molecular models for each:

If you don’t fully understand the graph above, click here to listen to my new jam!! :)

  1.   Draw molecular models from macroscopic observations.

Sketch (your image does not have to be perfectly drawn and colored) an image that shows the following phase change at the microscopic level and provide and example of where each phenomenon takes place at the macroscopic level.

  1. freezing
  2. boiling
  3. evaporating
  1. Explain why solids have a more ordered, regular arrangement of their particles than liquids. Show using molecular models/diagrams

  1.  Explain how solids, liquids and gases are different at room temperature.

  1. Describe melting on a molecular level and draw a diagram to explain what is happening to the particles.

  1. Explain how the addition or removal of energy can cause a phase change.

  1. What phase changes release energy? and what phase changes require energy?

  1. Explain why and show how freezing is an exothermic change of state.  

  1. Describe the relationship between the temperature and pressure of a gas. Show how such at the microscopic scale can cause a visible change at the macroscopic scale.  Example (egg in flask phenomenon & water bottle with balloon phenomenon).

  1. Describe how molecules transfer energy by bumping into each other.

  1. Describe the various states of matter in terms of the motion and arrangement of the molecules making up the substance.

  1. Explain changes in volume, pressure and temperature for gases as you increase kinetic energy.  Decrease the kinetic energy.  

  1. How is the periodic table organized? What are groups? Periods? Where are the Alkali metals? Alkaline earth metals? The halogens? The noble gases?

  1. A company plans to make an electronic device.  They need to use an element that has     chemical and physical behavior similar to that of Silicon but must have an atomic mass that is less than that of Lead. Use the periodic table to determine which element you would recommend and explain why you chose that element over other elements

  1. Xenon, a nonreactive gas used in strobe lights, is a poor conductor of heat and electricity.  Without looking at the periodic table, explain how you would use the information provided to determine whether Xenon is a metal, nonmetal, or metalloid? Where would you expect to find it on the periodic table? In which group?  Now check the periodic table to see if you were correct

  1. Explain why chlorine, bromine, and iodine have similar chemical properties although they are all at different phases at room temperature

  1. Determine the element with similar chemical properties to that of lead but can be used in making computer chips because it happens to be a metalloid with a low atomic mass.

  1. Differentiate between the following: Atom, element, compound, bond, electron.  Click here for a short video.

  1. Compare and contrast ionic and covalent bonds including the nature of the bonds.  Click here for a video comparing the 2.  Click here for a video on covalent bonding.

  1. Describe the differences between metals, nonmetals and metalloids.  Click here for a tutorial.

  1. Use the periodic table to indicate whether the following compounds are ionic or covalent. Work each problem using either the diagram for transfer or sharing
  1. HF
  2. CaS
  3. H2O
  4. LiI

  1. How many bonds can each of the following atoms form? Explain how you were able to determine the number using what you learned about noble gas configuration/octet rule
  1. Nitrogen
  2. sulfur
  3. Oxygen
  4. fluorine
  5. A halogen
  6. Carbon

  1. Use the periodic table of elements to determine whether the following pair of elements will form ionic or not. If so, construct an atomic level diagram show how and write the chemical formula
  1. Nitrogen and oxygen
  2. Calcium and fluorine
  3. Carbon and fluorine
  4. Lithium and sulfur

        

  1.  Write the formulas for the following ionic compounds and show you were able to use noble gas configuration to determine the chemical formula.

 If you are still confused about ions and ionic bonding Click here

 

  1. Explain why all of the following compounds will be covalently bonded, then draw the lewis structure.
  1. PCl3
  2. CBr4
  3. NH3
  4. F2
  5. Cl2
  6. O2
  7. N2

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  1. Describe the atomic model regarding empty space and the nucleus.  Click here for video

  1.  Identify the location, mass, and charge of each of the three subatomic particles within an atom. Click here for video on parts of an atom. Click here for a video on atomic mass and mass number.

  1. Provide the number of protons and electrons for the following: Click here for a tutorial that will help.
  1. Sodium atom
  2. Sodium ion with a charge of +1
  3. Calcium ion with a charge of +2
  4. oxygen atom
  5. nitrogen ion with a charge of -3
  6. chlorine atom
  7. chlorine ion with a charge of -1

      28.  Are the subscripts used correctly for the following ionic compounds? How do you know? For the ones used incorrectly, show why. Then, name each compound.

  1. Na2Br
  2. MgS
  3. MgCl
  4. LiBr2
  5. Ca2N3

29. Write the correct chemical formulas for the following compounds:

  1. Lithium Chloride
  2. Magnesium bromide
  3. Calcium oxide
  4. Calcium fluoride
  5. Aluminum chloride
  6. Aluminum oxide

           

30. Write out the chemical equation, and balance for each of the reactions below.

 

31.  What is a mole and how do we apply the mole concept in chemistry? Why is it important?

 

32.      How can chemists determine the number of moles from the mass of any element or compound?

 

 

33.      How can chemists determine the number of particles of any compound or element given the mass of the substance?

 

34.      How can chemists determine the mass of a particular product (compound or substance) in a chemical reaction given the mass of the starting material?

 

35.      A snowflake contains 10.8 X 1013 molecules of water.  How many mol of water does it contain?

36.   Sodium, which is a highly reactive shiny metal, reacts with chlorine, a toxic yellowish-green gas, to produce sodium chloride.  How many grams of salt will be produced if 13.3 X 102 grams of sodium metal is available?

37.   One disadvantage of burning propane (C3H8) is that carbon dioxide is one of the products.  The released carbon dioxide increases the amount of CO2 in the atmosphere and increases the effects of global warming. How many moles of CO2 would you say is produced when 86.3 moles of propane is burned in excess oxygen in a gas grill

38.    When hydrogen gas is cooled to sufficiently low temperatures, it condenses to form a liquid that can be used to power nonpolluting vehicles in which its reaction with oxygen (from the air) yields an exhaust containing only water vapor. If 3.96 X 103 g of hydrogen are used up for a trip to cedar point how many grams water vapor is released into the atmosphere?

 39. The exothermic reaction between liquid hydrazine (N2H2) and liquid hydrogen peroxide (H2O2) is used to fuel rockets.  The products of this reaction are nitrogen gas and water.  How many grams of nitrogen gas is released when 13.6 X 102 grams of hydrazine is used up?

40. One disadvantage of burning propane (C3H8) is that carbon dioxide is one of the products.  The released carbon dioxide increases the amount of CO2 in the atmosphere and increases the effects of global warming. How many grams of CO2 would you say is produced when 11.98 grams of propane is burned in excess oxygen in a gas grill?

41. How many grams of carbon dioxide are formed by burning 190.0 grams of carbon? 

42. When steam (water vapor) and carbon react, carbon monoxide (CO) and hydrogen are produced.  What weights of carbon monoxide will be formed by the action of 250000 g of steam on carbon? Write the chemical equation first.  

43. When steam (water vapor) and carbon react, carbon monoxide and hydrogen are produced. What weights of hydrogen gas will be formed by the action of 16000 g of steam on carbon?