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Molar Mass
Grams to grams
Limiting Reagent
Percent Yield
Chemistry Trivia
100
The molar mass is useful when converting between _______________ and ______________.
What is grams and moles?
100
This is the procedure for converting from grams to moles.
Divide by the molar mass.
100
This is the definition of a limiting reagent.

(Something like . . .)

What is the chemical that gets used up first in a reaction.  It is the chemical that limits how much product you can make.
100
This is the equation for calculating percent yield.
Percent yield = (actual yield / theoretical yield) x 100
100
Diamonds are made primarily of this element.
What is carbon?
200
This is the rounded molar mass of Na.
What is 23 g/mole?
200
Without using any numbers or specific chemical names, this is the general procedure for going from n grams of substance X to an unknown number of grams of substance Y.

n grams of X divided by molar mass of X

multiply by mole ratio

multiply by molar mass of Y

200
If you're making ham sandwiches.  Each sandwich needs 2 pieces of bread and one slice of ham.  If you have 30 pieces of bread and 20 slices of ham, this is the limiting reagent.
What is the bread?
200
If you got 45 out of 50 possible questions right on a test, this was your % score.
90 %
200
This is the most abundant element in the earth's atmosphere.
What is nitrogen?
300

This is the molar mass of Li2S.

What is 46 g/mole?
300

Fe2O3 + CO2 --> 2Fe + 3CO2


How much Fe2O3 is needed to obtain 92.8 g of Fe?

What is 133 g Fe2O3

300

2Cu + S --> Cu2S

This is the limiting reactant when 80 g of Cu reacts with 25 g of S.

What is copper?
300
If you actually produced 12.8 grams of a substance, but theoretically expected 13.6 grams, this was your percent yield.
What is 94%.
300
This is the chemical formula for hydrogen peroxide.

What is H2O2 

400

This is the molar mass of Na3PO4.

What is 164 g/mole?
400

2NaOH + CO2 --> Na2CO3 + H2O

This number of grams of CO2 are needed to react with 3.5 grams of NaOH.

What is 1.925 g CO2?

400
If you got 87% yield when you made 15.7 grams of a substance, what was your theoretical yield?
What is 18 g?
400

CaCO3 --> CaO + CO2

What is the theoretical yield of CaO if 24.8 g of CaCO3 is heated?

What is 13.9 g of CaO.
400
This is the most abundant metal in the earth's crust.
What is aluminum?
500

In the equation:

2Fe2O3 + C --> Fe + 3CO2,

this is the molar mass of carbon dioxide.

What is 44 g/mole?
500

SiO2 + 3C --> SiC + 2CO

When 50 g of silicon dioxide is heated with an excess of carbon, 32.2 g of silicon carbide is produced.  How many grams of CO are made if it CO shows the same % yield?

What is 45 g of CO?
500

N2H4 + O2 --> N2 + 2 H2O


You have 1,000 g of N2H4 and 1,400 g of O2.

How many grams of the excess reagent will remain after the reaction?

400 grams excess O2


1 - Determine the limiting reactant

2 - Use that limiting amount to determine how much of the excess is used.

3 - Subtract from the amount of excess reagent you began with.

500

FeCO3 + O2 --> 2Fe2O3 +4CO2

If 75 g of FeCO3 is heated with an excess of oxygen, 45 g of Fe2O3 is produced.


What is the percent yield of this reaction?

Check with Mrs. Brown
500
This element (which can be sold for as much as $68 million / gram) is often called the most expensive element.
What is Californium?