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Homework Help: Chemistry Concept Review

  1. Dec 5, 2005 #1
    I think I got these right but I wanted to check first before I took my test...

    The ones that don't have any answers are ones I need help with.

    Concept Review:

    1. Which of the following is most likely to form a cation?

    Xe

    Cl

    Ca

    S

    2. Which of the following is a chemical change?

    cutting paper

    spoiling milk

    freezing water

    dissolving sugar in hot tea

    3. The formula for Magnesium iodide is:

    MgI

    Mg2I

    Mg2I2

    MgI2

    4. List three common substances in your house that are pure compounds.

    water
    vegatable oil

    I'm kind of just pulling answers out now so I'll stop...
    :biggrin:

    5. Which of the following is an ionic compound?

    Al

    CaCl2

    CO2

    None of these is ionic

    6. A potassium ion is a cation and a chloride ion is an anion. What does this have to do with why potassium and chlorine form a bond?

    7. What is the name of the compound Pb(NO3)2?

    lead(ll) nitrite

    lead(ll) nitrate

    lead nitrate(ll)

    lead nitrate

    8. Which of the following is a compound?

    carbon

    lithium

    water

    oxygen

    9. According to the law of conservation of mass, when nitrogen gas and hydrogen gas react to form a compound, the mass of the compound will be ______________ the combined masses of the nitrogen and hydrogen.

    equal to

    greater than

    less than

    either greater or less than

    10. An example of a heterogeneous mixture would be

    salt

    water containing dissolved sugar

    water

    chicken noodle soup

    11. Which of the following is a physical property?

    color

    volume

    freezing point

    all of the above

    12. Multiply the following using significant digits:

    2.51 x 3.0007

    7.53

    7.5

    7.5318

    7.532
     
  2. jcsd
  3. Dec 5, 2005 #2

    cronxeh

    User Avatar
    Gold Member

    3. MgI2
    4. salt (NaCl) also
    7. lead (ll) nitrate
    10. chicken noodle soup
    12. you have 3 sig figs (2.51) therefore you should have 3 sig figs in answer. 7.53
     
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