Lesson - 4th 6th Wks

4th 6th Weeks - Final

Empirical and Molecular Formulas

Stoichiometry

Limiting Reactant

Percent Yield

Kinetic Molecular Theory

​Pressure

Boyle's Law

Charles' Law

Avogadro's Law

Ideal Gas Law

Dalton's Law ​

Empirical & Molecular Formulas

• Empirical Formulas are the reduced/simplest ratio of atoms

• Molecular Formulas are the actual ratio of atoms (not reduced)

• REMINDER- chemical formulas can be both empirical and molecular

  • example - water and carbon dioxide​

Multiple Choice

A molecule of carbon, hydrogen, and oxygen have an empirical formula C₅H₈O₂

What is the molecular formula if the molar mass is about 200g?

• C₅H₁₀O₂

• C₁₀H₁₆O₄

• C₂H₄O

Multiple Select

Find all of the formulas that would be considered in their molecular formula.

• H₂O

• C₆H₁₂O₆

• MgCl₂

• CO₂

Fill in the Blank

What is the empirical formula for C₆H₁₂O₆?

Multiple Select

Click on all of the compounds that would be in their empirical formula form?

• Ca2S2

• H₂O

• NaCl

• C₆H₁₂O₆

Stoichiometry

Stoichiometry is used to help chemists determine how much reactant and product is used in the reaction.

​

MUST have a BALANCED EQUATION​

Coefficients from the balanced equation gives you mole ratios​

grams to moles conversion factor is found on the Periodic Table

moles to particles conversion factor 1 mole = 6.02e23

moles to volume conversion factor is 1 mole = 22.4 L​

Fill in the Blank

2KI + Pb $$\rightarrow$$   PbI₂ + K

If 6.6 x 10²⁴ particles of KI react, how many moles of PbI2 will be produced?

Fill in the Blank

2H₂ + O₂ $$\rightarrow$$   2H₂O

If 294.25 grams of H2 are reacted, how many moles of O2 will be needed?

Put units with your answer.

Limiting Reactants Concept

1. the reactant that runs out first

2. the reagent that stops the reaction

3. the reactant that is completely consumed

4. the reagent that limits the amount of product that can be made

Multiple Select

Click all the explanations that talk about the limiting reactant or reagent?

• the reactant that will run out and limit the amount of product you can make

• the reactant that you have excess of when making the product

• the reagent that stops the reaction

• the limiting reactant (or limiting reagent) is the reactant that gets consumed first in a chemical reaction

Multiple Choice

2Al + 3I₂ ------> 2AlI₃

_{Which reagent will be completely consumed first if you have 10 moles of each reagent?}

• aluminum

• iodine gas

• aluminum iodide

Percent Yield

Actual Yield / Theoretical Yield x 100 = Percent Yield

Multiple Choice

What side of the arrow do you find any yield (actual or theoretical) in a balanced chemical equation?

• where ever the question puts it

• on the reactant side

• on the product side

• can be on either side

Multiple Choice

Which yield will be the smallest most of the time?

• actual yield

• theoretical yield

• percent yield

Fill in the Blank

For the balanced equation shown below, if the reaction of 11.4 grams of CO produces 10.5 grams of CH₃OH, what is the percent yield?

Round percent to the tenths place don't forget the percent sign

2H₂ + CO --> CH₃OH

Fill in the Blank

For the balanced equation shown below, the reaction of 20.9 grams of C2H4O produced 5.10 grams of CO2 in a lab, what is the percent yield?

2C2H4O + 5O2 → 4CO2 + 4H2O

Round percent to nearest whole number

Fill in the Blank

For the balanced equation shown below, if the reaction of 5.66 grams of C₆H₅F produces a 82.4% yield, how many grams of H₂O would be produced ?

C₆H₅F + 4O₂ => 6CO + 2H₂O + HF

Kinetic Molecular Theory​

How do gasses behave?​

Multiple Choice

Gas pressure is created by

• gas molecules colliding with surfaces
• gas molecules condensing to a liquid
• gas molecules hitting other gas molecules

• molecules hitting other molecules

Multiple Choice

• Flask 1 contains the most molecules

• Flask 2 contains the most molecules

• Flask 3 contains the most molecules

• Flask 4 contains the most molecules

Multiple Select

• Gases do not move in straight line
• Most of the volume of gas is empty space
• Gas particles are not in constant random motion
• Gas particles attract each other

Multiple Choice

A hypothetical gas that perfectly fits all the assumptions of the kinetic molecular theory is known as

• real gas

• ideal gas

• imaginary gas

• perfect gas

Multiple Select

What causes pressure?

• The particles hitting each other

• the particles hitting the INSIDE walls of the balloon

• temperature

  volume

• the particles hitting the OUTSIDE of the balloon

Gas Laws​

Multiple Choice

What is the formula for Boyle's Law?

• P₁V₁=P₂V₂
• P₁V₁/P₂V₂
• P₁V₂=P₂V₁
• P₁/V₁=P₂/V₂

Multiple Choice

Boyle's Law says when PRESSURE increases then the VOLUME must...

• Increase
• decrease

Multiple Choice

Which container will have a lower pressure?

• left
• right
• they both have the same pressure
• I don't know

Multiple Choice

Gases can be compressed. 

• True
• False

Multiple Choice

LeGarrette Blount decides to go scuba diving while on vacation in Mexico. As he swims deeper into the ocean, the pressure pushing on him increases. Based on the relationship in Boyle’s law, what would happen to the volume of a LeGarrette’s lungs with this increase in pressure?

• volume of the lungs would increase
• volume of the lungs would have no change
• volume of the lungs would double
• volume of the lungs would decrease

Multiple Choice

What is the formula for Charles' Law?

• V₁ /T₁=T₂ /V₂

• T₁V₁/T₂V₂

• V₁V₂=P₂V₁

• V₁/T₁=V₂/T₂

Multiple Select

What gas laws must you use Kelvin temperature in or your calculations will be wrong?

• Boyle's Law

• Charles' Law

• Avogadro's Law

• Ideal Gas Law

• Pressure

Multiple Choice

When the temperature of a gas decreases (with pressure and amount held constant), does the volume will ....

• be unaltered

• remains constant

• Increases

• decreases

Multiple Choice

Which of the following uses the concept of Charles’ Law?

• Hot air balloon

• Syringe

• Drinking straw

Multiple Choice

What is the variable for this number 22.4 L

• P
• T
• n
• V

Multiple Choice

What is the variable for this number 32^oC

• P
• T
• n
• V

Multiple Choice

What is the variable for this number 9.10 atm

• P
• T
• n
• V

Multiple Choice

What is the variable for this number 1.5 mol

• P
• T
• n
• V

Multiple Choice

Which law helps us find the moles of gas in a sample?

• Charles Law
• Boyle's Law
• Combined Gas Law
• Ideal Gas Law

Multiple Select

A 28.965 L sample of Kr experiences a change in pressure from 358.34 kPa to 729.71 kPa. The resulting volume is 14.224.

Name the law being used and is the data following the law?

• yes

• no

• Boyle's Law

• Charles' Law

• Ideal Gas Law

Multiple Choice

Which is a correct unit for R?

• L.atm/mol.k

• L.atm

• mmHg/mol.K

• L.atom/mol

Multiple Choice

Dalton's Law states...

• when pressure increases

  volume decreases

• that the total pressure exerted by the mixture of non-reactive gases is equal to the sum of the partial pressures of individual gases
• when temperature increases

  volume increases

• when the moles of a gas decrease

  volume decreases

Multiple Select

If 3.25 mol of Ar occupies 100. L at a particular temp and pressure.

2.89 moles of Ar occupy 435 liters under same condition.

Define the law and is the law followed based on the data?

• yes

• no

• Charles' Law

• Boyle's Law

• Avogadro's Law

Multiple Select

A mole of any substance is equal to ____.

• 6.02e23

• 6.02 x 10²³

• 6.02 x 10^-22

• 6.02 x 10^-23

Multiple Choice

What would a closed bag of chips do in outer space?

• explode

• implode

• nothing

Multiple Select

When using the Ideal Gas law, what units CANNOT be used in your calculations when using the variable "R" constant 0.0821?

• atmospheric pressure

  (atm)

• torr

  mmHg

  psi

• Celsius 

  (C)

• kiloPascals

  (kPa)

• Kelvin

  (K)