Stoichiometry

Part 1

100

Define stoichiometry.

A) A section of chemistry related to stocks

B) A section of chemistry that involves reactants and/or products in a chemical reaction to determine its quantitative data. 

C) A section of chemistry that studies the chemistry of molecular subunits

B) A section of chemistry that involves reactants and/or products in a chemical reaction to determine its quantitative data.

200

1. True or False?

 Stoichiometry is used to determine the quality of products and reactants that are needed or produced in a reaction?

False

300

2 Mg + O₂ --> 2 MgO

If you react 15 grams of Mg with 20 grams of O₂, which one is the limiting reagent?

Mg

400

2 LiNO₃ + PbSO₄ --> Li₂SO₄ + Pb(NO₃)₂

How many grams of lithium nitrate (LiNO₃) (68.93 g/mol) will be needed to react with lead(II) sulfate (PbSO₄) to produce 250 grams of lithium sulfate (Li₂SO₄) - (109.94 g/mol)?

313.5 g

Part 2

100

What is a limiting reagent? 

A) A reactant that gets consumed first in a chemical reaction

B) A reactant that binds to an element first in a chemical reaction

C) A reactant that determines the quality of a chemical reaction’s product

A) A reactant that gets consumed first in a chemical reaction

200

What is Percent Yield?

Actual/Theoretical  X 100%

300

2 KClO₃ --> 2KCl + 3 O₂

How many moles of KClO₃ must decompose to make 9 moles of gaseous oxygen?

6 moles

400

4 Al + 3 O₂ --> 2 Al₂O₃

How many moles of solid aluminum are required to produce 4.5 moles of aluminum oxide?

9.0 moles

Part 3

100

What is an excess reagent? 

A) A reactant that is not completely used up once the reaction finishes

B) The waste product of an element after fractional distillation

C) An element that has a higher amount of protons in a chemical reaction

A reactant that is not completely used up once the reaction finishes

200

Maximum Product is the same as ____

Theoretical Yield

300

Is this true? Mole ratios are found from the balanced equation of a reaction. 

 

True

400

What is the molar mass of Mg(OH)₂?

58.3 g/mol

Part 4

100

What is the molar mass of Calcium chloride(CaCl₂)?

110.98 g/moll

200

Define mole ratio.

A) The ratio between the amount of moles that two compounds have in a reaction

B) The ratio between the distance of moles of an element from its surroundings

C) The ratio between the mass of moles that two compounds have in a reaction

The ratio between the amount of moles that two compounds have in a reaction

300

Is this true? You must convert grams to moles to do stoichiometry. 

 

True

400

From the equation N₂ + 3H₂ → 2NH₃, how many moles of hydrogen are needed to react with 1 mole of nitrogen?

3 moles

Part 5

100

When in doubt, always change to ___

moles

200

Which of these measurements can be used in stoichiometry?

A) Moles

B) Mass

C) Volume

D) All of the above

D) All of the above

300

Which of the below is true for limiting reagents?

A) It is completely  consumed in a chemical reaction

B) It is consumed and it turns into excess reagents as waste

A) It is fully consumed

400

Which of these products is NOT a product of stoichiometry?

-Soap

-Chocolate bars

-Gasoline

-None of the above

None of the above