Stoichiometry

Chapter 7 Definitions

100

A compound with this quality readily absorbs moisture, even from the atmosphere

What is hydroscopic?

200

This reactant will run out first, limiting the amount of product made

What is the limiting reactant?

300

The number below the chemical symbol on the Periodic Table tells you two things:

What are the mass of a single atom in amu and the number of grams you need to collect to have a mole of those atoms?

400

This allows you to "count" atoms and might be referred to as "chemistry recipes"  

What is Stoichiometry?

500

The conversion relationship you get from chemical equations are _____. 

What is exact?

I think it's a mole!

100

Not just a cylindrical mammal, but also this certain number of atoms or molecules 

What is 6.02 x 10²³? 

200

6.02 x 10 ²³ is credited to this fine Italian gentleman.

Who is Amedeo Avogadro?

300

Avogadro's constant was discovered by this scientist

Who is Jean Baptiste Perrin?

400

48.62 g of Mg is equivalent to this amount of moles of Mg. 

What is two (2) moles of Mg?

500

Having 5 moles of Mercury means you have how many grams?

What is 1,002.95?

Molar Infestation of Chemical Equations

100

The formation reaction for Methanol is 

2C + 4H₂ + O₂ --> 2CH₄O.

If you wanted to make 100.0 moles of methanol, you would need this many moles of hydrogen and this many moles of oxygen. 

What is 200.0 moles of H₂ and 50.00 moles of O₂?

*Extra point for team if answer is given with correct number of significant figures; 2 extra points if answer includes correct number of significant figures AND written as homonuclear diatomics.

200

When a chemist makes methanol (using equation from previous question), she starts with 24.0 grams of carbon, 10.0 grams of hydrogen, and 40.0 grams of oxygen.  In the end she makes methanol, but then realizes she has 2.0 grams of hydrogen and 8.0 grams of oxygen left over.  Carbon was

What is the limiting reactant?

300

A chemist is making N₂F₄, according to the following chemical equation: 

5F₂ + 2NH₃ --> N₂F₄ + 6HF

If he adds 150 moles of F₂ to an excess if NH₃, he will make this many moles of N₂F₄

What is 129.5 grams?

400

A chemist wants to make Na₂S according to the following chemical equation:

16Na + S₈ --> 8Na₂S

When she adds 15 moles of Na to 1 mole of S₈, she discovers that this element is the limiting reactant. 

What is sodium?

500

A chemist is running the following chemical reaction:

4FeCr₂O₇ + 8K₂CO₃ + O₂ -> 2Fe₂O₃ + 8K₂CrO₄ + 8CO₂

He has plenty of oxygen and K₂CO₃, but only 115 grams of FeCr₂O₇, so he can only make this amount of K₂CrO_4.

What is 164.0 grams?

Chapter 8 Definitions

100

This is the difference between a quantity's measured value and its true value

What is experimental error?

200

The Actual Yield divided by Theoretical Yield multiplied by 100% is this

Whay is the Percent Yield?

300

This is a formula that shows the simplest ratio of elements present in a compound.

What is the empirical formula?

400

This formula shows the actual number of each element in a compound.

What is the molecular formula?

500

This is an ion composed of two or more atoms that are covalently bonded to one another

What is a polyatomic ion?

Common Polyatomic Ions

100

The ion for this polyatomic ion is NH₄⁺

What is Ammonium?

200

This is the formula and charge for Hydronium

What is H₃O⁺?

300

The _____ is as important as the chemical formula in polyatomic ions.

What is the charge?

400

This is the formula and charge of Hydroxide.

What is OH^-?

500

This ion is written as PO₄​^3-​​​

What is Phosphate?