Welcome to Murph's World!

Hello Fellow Chemists,

Here is some information that you will find useful: 

 

Today's Mission:

• Read the information below, starting with "How to Access Lessons." 
• Look over the information in tab at the top of the blog that pertains to your class (for example, SCH3U Intro).  
• You and your parent/guardian must sign the Course Information Sheet, Syllabus and Safety Contract. 
  
• To save paper, write "I have read and understood the CIS, syllabus and safety contract.  Signed __________(you)    ________(parent)" on a piece of paper.  Send me this through an Edsby message.
• Do the Diagnostic Quiz at the bottom of that same tab.
  

How to Access Lessons:

All lessons (many with accompanying videos - mainly made by me), homework and answer keys can be found on this blog. 

A course timeline, with hyperlinks to the appropriate blog lesson, is posted on Edsby.

  

How to Access Help:

You can seek out help/clarification when the need arises by asking during class or contacting me on Edsby.  

I also strongly encourage you to start/become a part of a group chat.  The hive mind is typically stronger than the individual.  😃

SNC 2P/SCH 3U/SCH 4C/SCH 4U - Chemistry - Valences

Valences

A valence is the real or apparent charge on an atom in a compound.

Grab a fresh Periodic Table and several coloured pencils and let's get cracking.

 

This chart is also useful for determining valences.

 

 

SCH 3U - SCH 3U Review

This is the exam review.  It is worth your while to be sure that you can do the questions in this booklet, as it will aid your success on the exam and in future chemistry courses (I'll see some of y'all next year 😉- actually, I won't - I'll be retired - woo to the hoo!!).

The most crucial concepts at which you MUST be proficient are:

• nomenclature (surprise, surpise) ↝ #3-8
• bonding ↝ #14, 18
• predicting products ↝ #20,
• using the Activity Series of Metals and the Solubility rules (as appropriate) ↝ #20
• writing out balanced equations, with the correct state symbols ↝ #20
• writing out total ionic and net ionic equations (as appropriate) ↝ #20
• calculations involving moles, molar mass, mass ↝ #21, 22, 28, 32
• calculations involving pressure, volume, temperature ↝ # 52-56
• calculations involving moles, volume, concentration ↝ # 38, 41, 45, 46, 48
• acid and base definitions and characteristics ↝ #47
• pH scale & calculations ↝ # 39, 40, 49
• stoichiometric calculations ↝ #33, 34, 44, 57-59
• intermolecular forces and properties ↝ #35, 36

Obviously, there are a lot of concepts and skills that you must bring with you into the next step in your chemistry education. You should be able to do all of the above questions without looking at notes/textbook/internet or asking for help from friends/family/tutor.  It is only fair to warn you that the SCH 4U chemistry course is a large step up in terms of time, effort and ability compared to SCH 3U.  So, be prepared. 

Well folks, there's nothing left but the cheering.  We made it.  We survived and we prevailed. 

Homework:

 

 

  
Answers:

 

 

 

 

 

 

SCH 3U/4C - Acid-Base Titration

Acid-Base Titration

A titration is a chemical analysis involving the progressive addition of a solution of known solute concentration, called the titrant, into a solution of unknown concentration, called the sample. 

The purpose is to determine the quantity of a specified chemical in the sample, from which the concentration and/or the molar mass of the chemical may be determined.  This is possible because the titrant and the sample contain substances that react according to known stoichiometry. 

Generally, the sample is placed in a flask and the titrant is placed in a burette. 

     

In an acid-base titration, we are interested in the point at which the number of moles of acid is equal to the number of moles of base; this is referred to as the equivalence point.  An indicator is chosen so that the endpoint occurs precisely at the equivalence point.  

n_a = n_b

c_aV_a = c_bV_b

                 c_a(25.0 mL) = (0.10 mol/L)(34.6 mL)

              c_a = 0.14 mol/L

Here is a video, showing how a titration is performed.

 

Homework:

Practice Problems p. 466 # 1-3 (hint: write out the balanced equation between the acid and the base first as stoichiometric ratios matter.)

 

 

Answers:

Success Criteria:

- know the Arrhenius and Bronsted-Lowry definitions of acid and base

- be able to define and explain the use of an indicator

- be familiar with the hydronium ion and what it represents

- know and apply the definition for ionization, dissociation, autoionization

- know the difference between a strong and weak electrolyte

- know the difference between a dilute and concentrated electrolyte solution

- be familiar with examples of strong, weak, mono-/di-/tri-/polyprotic acids

- be familiar with examples of strong, weak bases

- be able create an acid/base reaction and then label acid-conjugate base and base-conjugate acid pairs

- know the properties of acids and bases (taste, colour with litmus, etc)

- be able to draw the pH scale and label the regions

- be able to do acid-base calculations: pH, [H+], [OH-], titration (caVa = cbVb)

- know the info in the Acid Rain reading

- be able to create a balanced equation for an acid-base neutralization reaction 

- know the definitions and theory associated with titration

Acid-Base Review - do not do #6, 9, 13, 17

 

Answers:

SCH 3U/4C - Neutralization Reaction

Neutralization of an Acid & a Base

Mixing together equal amounts (numbers of moles) of an acid and a base results in neutralization reaction (another double replacement reaction).  The mixing of an acid and a base always produces a salt (ionic compound) and water.  The products, the salt and water, are both neutral and the resulting solution has a pH of 7.

Acid  +  Base  →  Salt (Ionic Compound)  +  Water

HCl(aq)  +  KOH(aq)  →  KCl(aq)  +  HOH(l)

2HNO₃(aq)  +  Ca(OH)₂(aq)  →  Ca(NO₃)₂(aq)  +  2HOH(l)

• note: it doesn't matter whether you write the formula for water as HOH or H₂O.

 

 

Now, go on to to the Acid-Base Titration lesson.

Homework:

Complete the word equation and write a balanced equation for the reaction of the two given aqueous solutions in each case.  Be sure to include state symbols (hint: use your solubility rules when appropriate).

(a) sulfuric acid + sodium hydroxide →

(b) hydrobromic acid + magnesium hydroxide →

Answers:

sulfuric acid + sodium hydroxide → sodium sulfate + water

H₂SO₄(aq)  +  2NaOH  →  Na₂SO₄(aq) +  2H₂O(l)

 

hydrobromic acid + magnesium hydroxide → magnesium bromide + water

2HBr(aq)  +  Mg(OH)₂  →  MgBr₂(aq)  +  2H₂O(l)