Chemical Quantities Lesson

Chapter 8- Quantities in Chemical Reactions

​Presenter

​

Dr. Luis Bello​

Previous... Chapter 7- Chemical Reactions 

7.2 Evidence of a Chemical Reaction 

7.3 The Chemical Equation 

7.4 How to Write Balanced Chemical Equations 

7.5 Aqueous Solutions and Solubility: Compounds Dissolved in Water 

7.6 Precipitation Reactions: Reactions in Aqueous Solution That Form a Solid 

7.7 Writing Chemical Equations for Reactions in Solution: Molecular, Complete Ionic, and Net Ionic Equations 

7.8 Acid-Base and Gas Evolution Reactions 

7.9 Oxidation-Reduction Reactions 

7.10 Classifying Chemical Reactions 

Checking Comprehension

Multiple Choice

What substance is oxidized in the following reaction? 
Fe⁺² + MnO₄  → Fe⁺³ + Mn⁺²   

• Fe⁺²
• Mn⁺³
• Mn⁺²
• MnO₄

Multiple Choice

In the reaction
2Ca(s) + O₂(g) → 2CaO(s), calcium is...

• Reduced
• Synthesized
• Oxidized
• None of the above

Multiple Choice

Which is the correct net ionic equation for the reaction of AgNO₃ and CaCl₂?

• Ca²⁺(aq) +  2Cl^- (aq) → CaCl(s)
• Ag⁺(aq)  +  Cl^- (aq) → AgCl(s)
• Ag +  Cl  →  AgCl
• Ag⁺  +  Ca²⁺   →Ag₂Ca (s)

Multiple Choice

What are the reactants in the chemical equation pictured?

• CH₄ and CO₂

• CH₄ and O₂

• CO₂ and H₂O

• O₂ and H₂O

Multiple Choice

What type of reaction involves one element replacing another element in a compound?

• Single Displacement Reaction

• Double Displacement Reaction

• Synthesis Reaction

• Decomposition Reaction

Multiple Choice

What type of reaction involves 2 substances combining to form 1 new compound?

• Decomposition Reaction

• Single Displacement Reaction

• Double Displacement Reaction

• Synthesis Reaction

Multiple Choice

What type of reaction involves the breaking down of a substance into simpler substances?

• Single Displacement Reaction

• Double Displacement Reaction

• Synthesis Reaction

• Decomposition Reaction

Multiple Choice

The right side of the equation below is called the

• products
• reactants

Multiple Choice

The left side of the equation below is called

• Products
• Reactants

Multiple Choice

A substance that is formed as the result of a chemical reaction is a __________________

• Product

• Reactant

• Starters

• Enders

Multiple Choice

A substance that is formed as the result of a chemical reaction is a __________________

• Product

• Reactant

• Starters

• Enders

Chapter Outline

8.3 Making Molecules: Mole-to-Mole Conversions 

8.4 Making Molecules: Mass-to-Mass Conversions 

8.5 Limiting Reactant, Theoretical Yield, and Percent Yield 

8.6 Limiting Reactant, Theoretical Yield, and Percent Yield from Initial Masses of Reactants 

8.7 Enthalpy: A Measure of the Heat Evolved or Absorbed in a Reaction 

Mole-to-Mole Conversions 

Mass-to-Mass Conversions

Limiting Reactant

Theoretical Yield, and Percent Yield

Multiple Choice

What is a limiting reactant?

• the reactant that determines how much product can be made
• the reactant that is in excess
• the product that you can make the most of
• the amount of reactants that react with each other

Multiple Choice

2 KClO₃ → 2 KCl + 3 O₂
How many moles of oxygen are produced when 6.7 moles of KClO₃ decompose completely?

• 6.7 mol
• 1.0 mol
• 10.1 mol
• 4.5 mol

Multiple Choice

2H₂  +   O₂  →  2H₂O
How many moles of oxygen are consumed if 8 moles H₂ are used?

• 2
• 4
• 6
• 8

Multiple Choice

Use the equation 2 Al + 3 Cl₂ ---> 2 AlCl₃.  If 2 moles of aluminum and 2 moles of chlorine are reacted, identify the limiting reactant.

• AlCl3
• Cl2
• Al

Multiple Choice

You need 2 pieces of bread, 1 tablespoon of peanut butter and 2 tablespoons of jelly to make a sandwich.  If you have 10 pieces of bread, 4 tablespoons of peanut butter and 20 tablespoons of jelly, what is the limiting reactant?

• bread
• jelly
• peanut butter
• sandwich

Multiple Choice

What do we mean by the term standard conditions

• 1atm, 20C and 1moldm³

• 1atm, 0K and 1moldm³

• 10atm, 273K and 10mol/dm³

• 100kPa, 298K and 1mol/dm³

Multiple Choice

Match the definition below to the correct term.

The enthalpy change that takes place when one mole of a compound is formed from its elements in their standard states under standard conditions.

• The enthalpy of neutralisation

• The enthalpy of combustion

• The enthalpy of formation

• The enthalpy of reaction

Multiple Choice

ΔH value in an endothermic reaction is a positive number.

• True
• False

Multiple Choice

Which symbol represents Enthalpy change?

• ΔH

• ΔT

• ΔG

• ΔS

Multiple Choice

Endothermic reactions feel

• warm
• cold

Multiple Choice

How do you calculate Enthalpy of a reaction?

• ΔH = ΔH_products - ΔH_reactants

• ΔT = q / mC

• ΔG = ΔH -TΔS

• E = mc²

Multiple Choice

What type of reaction is shown in the graph?

• endothermic reaction

• exothermic reaction