CHEMICAL REACTIONS-Wednesday October 31, 2012

By: Siham Sirage

Summary

  • Today in class, a [[@#|quiz]] on molecular compounds was carried out
  • Reviewed properties and changes in matter
  • We had also began the new unit of Chemical Reactions
  • A practice worksheet on chemical reactions was given

Properties and changes in Matter

  1. PHYSICAL CHANGE
  2. CHEMICAL CHANGE
  3. CHEMICAL PROPERTY
  4. PHYSICAL PROPERTY

Physical change: a change in a [[@#|substance]] without changing the identity of it Ex. grinding
Chemical change: changing a substance into another Ex. charcoal being burned which consists of carbon and oxygen would change into carbon dioxide
Chemical property: the ability of a substance to turn into another Ex. [[@#|[[@#|Iron]]]] has the ability to rust by combining with oxygen
Physical properties: are observed and can be measured without the substances identity changing Ex. melting point

What indicates that a chemical reaction has taken place?


There are 5 indicators:
  • Emission of light as well as heat
  • A gas being formed
  • Precipitate being formed
  • Colour change
  • Odor being released

Synthesis:

When two or more simple substances or elements combine to form a complex substance
The general equation to follow is : A + B -> AB
Ex. 8Fe + S8 ->8FeS

Synthesis Reactions:

When Fe, Pb, Cu, or Sn react with F, O, or N the nonmetals will pull the metal into its highest oxidation number otherwise when the react in a combination reaction, they use their lowest charge when forming a new compound

Decomposition:

When a complex substance breaks down into two or more simpler substances
The general equation to follow is: AB-> A+B
Ex. 2NaCl -> 2 Na + Cl

Special Decomposition Reactions to know:


  1. All metal chlorates decompose into metal chloride + O2
Ex. 2KClO3 -> 2KCl + 3O2
2. Metal carbonates decompose into a metal oxide +CO2
Ex. CaCO3 -> CaO + CO2
3. Metal hydroxides decompose into a metal oxide + [[#|H2O]]
Ex. 2KOH -> K2O + [[#|H2O]]
4. Acids decompose into a non-metal oxide + H2O
Ex. 2HNO3 -> N2O5 + H2O

Single Displacement Reactions:

When one element replaces another in a compound. Metals replace nonmetals and vice versa.
The general equation to follow is: A + BC -> AC + B - If A is a metal
A + BC -> BA + C - If A is a nonmetal

Here are links to Decomposition, Synthesis, Single Displacement tutorials:
Decomposition:
http://www.youtube.com/watch?v=bQJvbmHD1Lg

Synthesis:
http://www.youtube.com/watch?v=Teaexn1luBA&feature=related

Single Displacement:
http://www.youtube.com/watch?v=Ph6xowy5fNc

[[#|HOMEWORK]]
  • Complete worksheet given in class for Friday
  • [[#|Study]] for unit [[#|test]] on nomenclature tomorrow
  • Prepare a data table for the chemical reactions lab taking place on Friday November 2, 2012






Nomenclature Unit Test

November 1, 2012
Viththakan Arunthavanathan

Summary:

  • Completion of the Nomenclature Unit

Overview of the class today:


Today was the day of the nomenclature [[@#|unit]] test. The test took the entire period as it was compiled of 40 questions; 20 for writing the formula, and 20 for naming.
This test included of everything thus far in the nomenclature unit such as:
  • Binary compounds
  • Multiple valence elements ([[#|Roman numerals]] & classical naming)
  • Polyatomic Ions
  • HOFBrINCl
  • Acids (Binary, Oxy, and Derived Oxy)
  • Acid Radicals and Acid Salts
  • Hydrates, Peroxides, and Thio Compounds
  • Molecular Compounds

No other lessons were taught today as the test covered the whole hour.

*NOTE - This page should be visited in a few days as the test will be posted with correct answers. This is a great opportunity to go back and check what you did wrong!*


JUST BECAUSE IT'S DONE, DOESN'T MEAN YOU FORGET ABOUT IT!

That's right. The concepts in this unit are far too important to put away to the sides just like that. These concepts and skills WILL be re-visited in later tests, quizzes, and exams! Especially in the next chapter/unit, where you will be dealing with types of reactions, which requires you to write compound formulas as well as the names for them.

If nomenclature was not your strongest unit, make sure to keep getting practice with the time you have and seek extra help.
A few links for you to visit and further develop your understanding in this unit are:

Flashcards review: http://quizlet.com/4703226/nomenclature-review-flash-cards/
SparkNotes full review: http://www.sparknotes.com/testprep/books/sat2/chemistry/chapter13.rhtml
Nomenclature basics (video):


Homework:

  • Create and observation table for tomorrow's 'types of reactions' lab
  • Finish up the worksheets on synthesis and decomposition reactions for Monday

Reminders:

  • Try to bring your safety goggles if you own one
  • Don't forget to bring an observation table or else you will not do the lab!
  • Don't miss or be late for class, as you will be doing a lab tomorrow!




Types of Chemical Reactions Lab Experiment

November 2nd, 2012
Viththakan Arunthavanathan

Summary:

  • The lab experiment
  • The follow-up assignment for the lab

Overview of the class today:


Today, students did a lab where they encountered the different types of chemical reactions. With a partner, the students went around seven different stations where they experienced different chemical reactions. Students were to observe what they saw throughout the lab and note it down on their observation table. This lab took just about the whole hour as no new lessons were taught in class today. The students were given a follow-up assignment which involved a few questions based on the conclusions of this lab experiment.
The criteria for the follow-up assignment:
  1. Balance chemical equations (Include the states)
  2. State the type of reaction
  3. Post-lab discussions questions
  4. Observation table (both good copy and rough data table)
  5. References (Ms. Wilson, Mr. Navaratnarajah, and your lab partner)

*NOTE - THIS IS NOT A FORMAL LAB REPORT AND SHOULD ONLY CONSIST OF THESE THINGS*

If you are not quite sure on how to answer some of the questions about the reactions, these sites may be helpful to you:
Video (not all reactions covered, but the main ones):



Endothermic and Exothermic reactions:
http://chemistry.about.com/cs/generalchemistry/a/aa051903a.htm

http://misterguch.brinkster.net/6typesofchemicalrxn.html

*Although these websites may separate them or not have them, there are 7 types of reactions that we study them as. Synthesis, decomposition, single displacement, double displacement, combustion, exothermic, and endothermic are the 7 types of reactions.*

Homework & Reminders:

  • The two worksheets given on Wednesday needs to be completed for Monday
  • Lab follow-up assignment due a week from today




Copper (II) Suflate; one of the lab substances
Copper (II) Suflate; one of the lab substances




Single and Double Displacement Reaction

November 5, 2012
Viththakan Arunthavanathan

Summary:

  • Single displacement reactions
    • Activity series
    • Reactivity of Halogens
  • Double displacement reactions

Overview of the class today:


In class today, students were taught two new reactions called single displacement and double displacement reaction. They were given two sheets explaining how to work with and recognize these reactions when it is given in front of them. Students also received their 'one page lab report' as well as their nomenclature unit test.

Single Displacement Reaction:


This reaction occurs when an element switches spots with another in a compound. Typically, a metal will replace a metal (cation replaces cation), OR a non-metal will replace a non-metal (anion replaces anion).
General equation: A + BC --> AC + B (this would be if A is a metal) OR A + BC --> BA + C (this would be if A is a non-metal)
Note - H2O breaks up into H+ and OH-, NOT H+ and O2- ALSO Hydrogen can replace a metal to create hydrogen gas in this type of reaction, although it is not a metal

Activity Series:


To understand the reactivity of metals, the activity series shows these reactivities where it is more reactive near the top and less reactive near the bottom.

Please
Potassium
K
Cold water (min. condition)
Send
Sodium
N
Cold water (min. condition)
Little
Lithium
Li
Cold water (min. condition)
Charlie
Calcium
C
Cold water (min. condition)
McArthy
Magnesium
Mg
Hot water (min. condition)
A
Aluminum
Al
Hot water (min. condition)
Zebra
Zinc
Z
Steam (min. condition)
In a
Iron
F
Steam (min. condition)
Nice
Nickel
Ni
Acid (min. condition)
Tin
Tin
Sn
Acid (min. condition)
Lined
Lead
Pb
Acid (min. condition)
High
Hydrogen
H
-
Crate
Copper
Cu
-
Marked
Mercury
Hg
-
Special
Silver
Ag
-
Good
Gold
Au
-
This chart helps us understand which metals have high reactivities as well as which metals react with water as shown above.
For example: Fe(s) + CuSO4(aq) --> FeSO4(aq) + Cu(s) --- This is because Fe is higher up on the chart than Cu, thus it is more reactive and can replace it in a single displacement reaction.
Ni(s) + NaCl(aq) --> In this case, Nickel cannot replace Sodium because sodium is much more reactive, as to why it is higher up on the chart.
For the reactivity with water: Na(s) + H2O(l) --> NaOH + H2(g) --- This is because you can see from the chart that sodium reacts with cold water.
Cu(s) + H2O(l) --> In this case, Copper cannot react with water according to the chart.

*NOTE - All metals have a certain place on this series, but these are common metals that you would regularly see. Also, if you do not know what the metal's valence is, you should go with its most common one (the bold number out of the valences on the periodic table). Lastly, this chart does NOT have to be memorized.*

Reactivity of Halogens:


There is also an order of reactivity in the family group of halogens for you to better understand which element can replace which in a single displacement reaction.
The chart on the right shows the order of reactivity.external image Halogen%20Reactivity%20Table.bmp
For example: F2(g) + CuCl2(aq) --> Cl2(g) + CuF2(aq) --- This is because, according to the chart Fluorine is more reactive than Chlorine, thus it can switch spots with it.
I2(s) + CuCl2(aq) --> In this case, Iodine cannot replace Chlorine, because it is less reactive according to the chart.

Double Displacement Reaction:


This is a reaction where a metal and metal switch places with each other, or in other words, a cation switches places with another cation in different compounds.
*NOTE - The activity series is only for single displacement and NOT USED here*
The general equation: AB + CD --> AD + CB
For example: AgNO3(aq) + NaCl(aq) --> AgCl(aq) + NaNO3(aq)

Special cases: One of the two [[#|products]] decomposes
Example: NH4Cl + NaOH --> NaCl + NH4OH ... HOWEVER, the Ammonium hydroxide can be further broken down so it turns into...
NH4Cl + NaOH --> NaCl + NH3 + H2O(l)
*Note - These cases are when there is H2CO3 (H2O and CO2), H2SO3 (H2O and SO2), and NH4OH (NH3 and H2O)*

Acid/Base Reaction: A special case of double displacement, also known as 'neutralization' where and acid and a base react to form a salt and water.
*NOTE - Salt does NOT mean NaCl, rather an ionic compound*
General Equation: Acid (H+) + Base (OH-) --> Salt + H2O
Example: HCl(aq) + NaOH --> NaCl(aq) + H2O(l)

If you need more information visit these links:

http://www.horton.ednet.ns.ca/staff/richards/Chem11/Chapter7_ChemicalEquations/DOUBLE%20DISPLACEMENT%20REACTIONS.html

(In this, the activity series is a bit different, but stick to the way you were taught in class)
http://www.horton.ednet.ns.ca/staff/richards/chem11/chapter7_chemicalequations/single%20displacement%20reactions.html

This video is quite helpful (but VERY basic):


If you need to refer to the textbook as well, pages 164-177 give you the lessons on these two reactions.

Homework and Reminders:

  • The sheet with single and double displacement practice problems
  • Get nomenclature test signed
  • Tomorrow is a lab! Bring your safety goggles if you have!




Day 43 - Types of Chemical Reactions- Activity Series LAB

Date: Tuesday, November 6, 2012
By: Jove Garcia

Summary

The Lab for "Types of Chemical Reactions - Activity Series" was carried out today.

Pre-Lab Requirements

  • Students were to have their Nomenclature Unit Test Signed and shown to teacher (and previous unit test, if not shown already)
  • Students were to have their lab worksheet obtained the day before
  • Students were to bring goggles (if they had their own)
  • Students were to predict the reactions on the worksheet based on the activity series learned earlier this week
    • If there was a reaction, a balanced chemical formula was required to be filled in the designated boxes
    • If no reaction was predicted, the boxes were to be indicated as "No Reaction"

Lab Overview

  • Once worksheets were filled, students found partners and had their sheets confirmed for completion by teacher
  • Students obtained spot-plates and the metal elements necessary for the lab
  • Students were to travel to every station that had the different types of acids/liquids that were to be separately experimented with each metal obtained previously
  • Reactions were to be observed and after a couple of minutes, students were to verify their earlier predictions and balanced chemical equations
  • The smaller boxes on the top-left hand side of each square were to be checked if a chemical reaction was evident, if no, it was to be left blank or "X'd"
    • For each chemical equation, the state of matter was to be declared for the reactants and the products before handing in the lab worksheet to the teacher

*The Remaining Time In Class Was Used For Any Work In Chemistry That Is Still Unfinished*

- Lab sheet will be handed back within the week
- Due to this, further information/pictures/videos may be added

Additional Reminders
  • Tomorrow is a Friday schedule, so please do not come in the morning to the classroom
  • Mid-Term Report Overall Marks were handed out to today to be signed by parents and returned tomorrow

Homework
  • Friday's Lab Report due at the end of this week, get it done early
  • Finish Single Displacement & Double Displacement Worksheets if not done so already
  • Continue to look over previous "Types of Chemical Reactions" worksheets if you need clarification or refer to the notes above on earlier days for a simple walk-through
    • *Answers to these worksheets will be provided on later dates



Day 44- Types of Chemical Reactions- Combustion & Exothermic and Endothermic & Review

Date: Wednesday, November 7, 2012
By: Jove Garcia

Summary

Today's class was spent [[#|learning]] the next types of chemical reactions; combustion, exothermic and endothermic. A quick demonstration was also shown to the class as well
The students received sheets to be explained in detail.

Pre-Class Requirements

  • Students were to have their papers with their Overall Marks signed and shown to teacher today

Overview - Combustion Reactions

  • There are two types of combustion reactions
    • Complete Combustion - carbon dioxide and water are the only products (Blue flames are complete combustion)
      • Example: CH4 + 2 O2 (g) → CO2 (g) + 2 H2O (g)
    • Incomplete Combustion - instead of CO2 being produced, the products may be CO, CO2, and /or C (water is also a product) (Orange types flames are incomplete combustion)
      • Example: C2H4 + 2 O2 → 2 CO + 2 H2O (States would be similar to Combustion)

  • In some cases the hydrocarbon may also contain a nitrogen or sulfur, in which case NO2 or SO2 is also produced
    • Examples:
      • C21H24N2O4 + 27 O2 (g) → 21 CO2 (g) + 12 H2O (g) + 2 NO2 (g)
      • 2 C2H5SH + 9 O2 (g) →4 CO2 (g) + 6 H2O (g) + 2 SO2 (g)


Overview - Energy In Chemical Reactions

  • Some reactions require more energy then is produced, others produce more energy then is required
    • Exothermic:a reaction that releases energy; energy is a product and is written on the right side of the arrow
      • Example: 2 H2 + O2 → H2O + ENERGY
    • Endothermic: a reaction that absorbs energy, energy is a reactant and is written on the left side of the arrow
      • Example: CaCO3 + ENERGY→ CaO + CO2

*Links to sites that explain this in more detail can be found under the daily notes for November 5*

*Example demonstration of an exothermic reaction was shown to class by teacher*
    • Aluminum foil and iron (lll) oxide was obtained
    • A "thermite" reaction took place by skimming both element/compounds together

Quick Video briefing on the Exothermic Reaction shown in Class



*The Remaining Time In Class Was Used For The Completion Of Today's Handouts*


Fun Facts Discussed In Class

  • CO (which is created from orange flames or incomplete combustion) is poisonous when inhaled
  • Magic is not real, magicians are actually scientists. CLICK ME

Additional Reminders
  • Do not forget to bring in pennies for the penny drive. Student, Meraj B., gave class in brief detail the Me to We initiative
  • For the Lab Report due Friday, a quick note is that peroxides break down to oxides and oxygen gas!
  • Again, more may be added to this Note so stay tuned if need be

Homework
  • Practice sheets were handed out today, complete the practice sections for tomorrow *Sheets to be posted on later dates if possible*
  • The Textbook Application Summaries section is expected to be completed for Monday
  • Lab Report due Friday, complete today, it will be much easier for you than starting tomorrow



Balancing Chemical Equations
Date: November 8th, 2012
By: Ewan Li
Summary
  • Two sheets were handed out today, one is for lesson and one is for homework and practice
  • Learned step by step of how to balance a chemical equation

Overview
All chemical reactions have two parts:
Reactants are the substances you start off with
Products are the substances you end up with

The Skeleton Equation
Skeleton equations are the chemical equations that will consist of the elements without it being balanced.
It uses formula and symbols to describe a reaction but does not indicate how many, which is not balanced.
For example : Li + H2O -----> H2 + LiOH
This is a skeleton equation that is not yet balanced.

Balancing equations
Matter can neither be created or destroyed because of the law of conservation of mass.
Only nuclear reactions will create new elements because it deals with the nucleus of the atom.
They can only be rearranged in a new orderly fashion into chemical equations.
Therefore the number of a specific atom will be the same on the other side.
Put the states of the compounds or elements if you know it.

Rules for balancing
  1. Assemble the correct formulas for all the reactants and products using the symbol "+" for reaction with and "---->" for compounds you will be ending up with.
  2. Count the number of atoms of each type appearing on both sides.
  3. balance the elements one at a time by adding the coefficients where you need more. (Always save hydrogen to balance last and oxygen to balance the very last)
  4. Treat polyatomic ions that repeat as if they were a single entity.
  5. Double check and make sure it is balanced
NEVER change a subscript to balance an equation and you only can change the coefficients.
NEVER put a coefficient in the middle of a formula Na2Cl , they must go only in the front > 2NaCl
When balancing equations, you must first list the different elements. Then put them in the same column on each side. After that calculate the number of atoms in each elements of reactants and products. *Never start with hydrogen or oxygen* Start with the highest number of atoms.
Trick- if the atoms of both sides can not balance due to having a even and odd number in the subscripts, you can always double everything.
example :
Balance everything else but hydrogen and oxygen first
C2H6 + O2 ---> 2CO2 +H2O
Then balance the hydrogen
C2H6 + O2 ---> 2CO2 +3H2O
At this point you can see that we have 2 oxygen atoms on the reactant side and 7 oxygen atoms on the product side. We cannot put 3.5 or 7/2 of an oxygen atoms so we can just double everything.
2C2H6 + O2 ---> 4CO2 +6H2O
This way we still have equal amounts of carbon and hydrogen but just not oxygen. Now it is easier to balance with 2 oxygen atoms on the reactant side and 14 oxygen atoms on the product side.
Finally
2C2H6 + 7O2 ---> 4CO2 +6H2O
This will be your final balanced chemical equation.
Video of how to balance chemical equations

Websites to practice chemical equations
http://www.sciencegeek.net/Chemistry/taters/EquationBalancing.htm
http://education.jlab.org/elementbalancing/index.html
http://science.widener.edu/svb/tutorial/rxnbalancingcsn7.html

REMINDERS
The Chemical reactions Lab will be due tomorrow, make sure to include references
Homework : the two sheets we got from today and the textbook application questions on the back of the Combustion will be due on monday
Bring MOAR PENNNIES
Quiz/Quest will be on next Monday or Tuesday
Permission forms for the field trip to the science centre will be going home next week to be signed.



Day 46 - Balancing Chemical Reactions Part 2

Date: Friday, November 9, 2012
By: Jove Garcia

Summary

Today, the class continued to practise their fundamental skills on balancing chemical equations from the previous day.

Pre-Class Requirements

  • Students were to hand in their Lab Reports from the Lab on November 2 today during the beginning of class

Class Overview

  • More practise on balancing chemical equations
  • Two new sheets on balancing practise was obtained today
  • Quick class example was shown to the class; expected to be completed if you wish for a 90 in the class
    • Example 1:Decomposition (Already Balanced)
      • Sufurous acid → Sulfur dioxide + water
      • H2SO3 (aq) → SO2 + H2O
      • Quick Note: Use equation that adds all elements in acid so that it would equal 0
      • Example for Above:(The number before the element represents the number of atoms each element has and the element will be replaced by its common charge)
        • 2 H + 1 S + 3 O = 02 (1) + S + 3 (-2) = 0 2 + S - 6 = 0 S - 4 = 0 S = 4
        • Therefore, the charge on Sulfur is 4 and when criss-crossed with the 2 charge on oxygen, it becomes SO2
    • Example 2:Single Displacement (Balanced in Equation)
      • Calcium + Silver nitrate → Calcium nitrate + Silver
      • Ca + 2 AgNO3 → Ca(NO3)2 + 2 Ag
      • Quick Note: The calcium was able to displace the silver based on the placement on the Activity Series

*The Remaining Time In Class Was Used For The Completion Of Today's Handouts*


Quick video for tips and tricks to balancing



To visit a website that can further clarify how to balance chemical equations with worksheets please CLICK HERE

Additional Reminders
  • Monday is the last day to bring in pennies, we did horrible on the food collection, let's do better on this one
  • Quiz will be within the following week, so continue to perfect your skills on balancing

Homework
  • Practise worksheets expected to be completed for own benefit
  • Textbook research sheet is due for Monday



Mining, Contamination and Green Chemistry


November 12,2012

By: Pratheep Rajan



Summary:


  1. Mining, Metallurgy and the Environment
  2. Detox for Contaminated Land
  3. Green Chemistry

Class Overview:


We were told to get out our textbooks and read pages 212-227 which covered the three topics above in the "Summary". After this was completed we were to do questions below:
  • Page 217 Question #'s 3-6,8a
  • Page 221 Question #'s 2, 4-6
  • Page 217 Question #'s 2, 5-8

Mining, Metallurgy and the Environment

  • Mining is the practice of removing minerals( a solid substance found in the Earth) from the ground
  • Metallurgy is the technology of taking and refining metals from the mining process, there are two types:
    • Traditional Smelting
    • Flash smelting (is more efficient, energy saving and overall better than traditional smelting)
  • Flotation is technique used to obtain ore( is a rock that contains enough if a valuable resource)
  • Acidic mine drainage can cause ground water and aquatic ecosystems to become contaminated
Copper Ore.JPGdownload1.jpg
Above from left to rught: copper ore, traditional smelting process

Detox for Contaminated Land


  • Remediation is a special process that removes contaminants from water and soil so that is safe for humans and animals
  • There are three types of remediation technologies:
    • Physical remediation uses a process named flushing
    • Chemical remediation involves techniques such as oxidization, electrolysis, stabilization and solidification
    • Bioremediation is the process of using living organisms that naturally clean contaminants from soil or water
      • Phytoremediation is a special type of bioremediation that uses plants instead of living organisms

Green Chemistry

  • Green Chemistry uses the idea behind this phrase to advocate the environmental betterment of chemical processes: "Why generate pollution if there is a greener alternative?"
  • Through green chemistry we know that a manufacturing process can be profitable and be good for the environment

Homework


Finish all of the questions assigned, they are listed above in the class overview.