mgo empirical formula lab

8/7/2019 MgO Empirical Formula Lab

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Determining the

Empirical Formula ofMagnesium Oxide


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Materials and Equipment 10-15 cm

magnesium

ribbon Crucible and lid

Clay triangle

Bunsen burner

and ring stand

Tweezers

Wire gauze Goggles, apron

Appropriate lab

attire

Scissors


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Procedures

1. Set up

ring stand,

bunsen

burner.


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Procedure

2. Mass the

emptycrucible

and lid.


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4. Find themass of

Mg.(How?)

4. Findthe mass

of Mg.(How?)


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4b. (Mass it in thecrucible plus lid, then

subtract. )


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5. Light the Bunsen burnerand adjust the flame to get

a good inner cone. Adjustthe ring to the best height.

(What height?)


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7. Heat the crucible.Using the tweezers, lift

the lid occasionally toallow air in. (It should

be red hot.)


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CAUTION:DO NOT look directly

at the burning Mg.

(It can blind you!)


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8.When the Mg is nolonger reacting with

oxygen gas in the air,turn off the flame.

(How do we know???)


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If its not glowing like

the sun anymore,

then its done.

Let it cool a bit


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9. Use the tweezers to putthe lid and crucible onthe wire gauze.

DO NOTput the hot

crucible directly on thetable top.


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Did I mention

DO NOTput the hot

crucible directly onthe table top?


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10. Allow the crucibleto cool. Mass it and

determine the mass ofthe magnesium oxide

product that youcollected.


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11. Empty the productinto the waste bin in

the front of class.Rinse the crucible and

wipe clean with a papertowel.


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12. Wipe your labbench and straighten

up your lab area.


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Create your data table What do you think should be on your data

table?


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MagnesiumO

xideD

ata Table1. Mass of crucible and lid.

2. Mass of crucible, lid, and Mg metal.

3. Mass of crucible, lid, and product

(after heating)

4. Mass of product (calculated from the

above data)


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Calculations

1. Mass of Mg metal:

2. Mass of magnesium andoxygen product:

3. Mass of oxygen that reacted:


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CalculationsD

etermine the

4. Moles of magnesium

5. Moles of oxygen


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Calculations

6.Empirical Formula of

Magnesium oxide.

7.% yield of Magnesiumoxide


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Discussion Questions

1. Were you surprisedwhen you compared the

mass of the magnesiumproduct after the reaction

compared with before.Why or why not?


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2. Why did we have toheat the magnesium to

such a high temperature?


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3. Why is the percent yieldimportant? (What does it

mean if your percentyield was 100%? What

does it mean if your %yield is low? Explain.)


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4. You found the empiricalformula for the oxide.

Does this mean we knowthe molecular formula

for magnesium oxide.Explain what you mean.

mgo empirical formula lab

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