What Concepts Should You Review Before a Chemistry Test?

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Key concepts to review before a chemistry test include identifying cations, recognizing chemical changes, and understanding ionic compounds. Important questions involve determining the formula for magnesium iodide, naming compounds like Pb(NO3)2, and applying the law of conservation of mass. Additionally, distinguishing between pure compounds and mixtures, as well as recognizing physical properties, is crucial. Significant figures play a role in calculations, emphasizing the importance of accuracy in answers. Mastering these concepts will enhance test preparedness.
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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
 
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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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