may 27th chem 11

Today we did an esterfication lab, and were tasked to attempt to create a remotely decent smelling ESTER from a alcohol and carboxylic acid.

Here are the list of possible smells we could of created:

isoamyl acetate-----> banana
isobutyl salicylate-----> raspberry
methyl salicylate----->wintergreen <------ the one we wanted
ethyl butyrate-----> pineapple
benzyl butyrate-----> cherry
ethyl propionate-----> rum
isopropyl acetate-----> perfume
benzyl acetate-----> peach
methyl butyrate----->apple
octyl acetate----->orange
propyl acetate-----> pear
ethyl phenylacetate-----> honey

So after a lot of effort..err...time, we finally created an Ester, after waiting for it to cool down we wanted to see if it smelled like wintergreen. The smell kind of reminded me of baloons...

After we finished the lab the foods class had to leave to cook for the sports banquet, so the remaining people were given the honor of taking inventory in the shelves.

may 25th chem 11

Today as a review, we got into groups and had to make the given molecules in a certain amount of time. We were also racing against each other to see who would finish first. The group that finished first was awarded with a starburst =)

Here is the list that we had to make:

1) Methyl butanoate
2) dichloroethane
3) 3 enthyl 2 pentanone
4) Acetic acid
5) dimethyl ether
6) ethyl propyl ether
7) 2 bromo 4,4 dimethyl pentanal
8) 2,3 pentadiol
9) ethylamide
11) 2, 2 dimethyl butylamide
12) propyl butanoate
13) Formaldehyde
14) Phenol
15) 3 choloro 3 methyl 2 butanone

may 20th chem 11

More functional groups?!?
Amides

- Double-bonded oxygen to carbon chain and NH2
- Use carbon prefix and -amide suffix
- Building block of proteins
-Nylon/Kevlar/Penicillin/LSD

Amines

- Contains nitrogen with carbon chains
- Make up amino acids (amine and carboxyclic acid)
- Alkyl prefix with -amine ending
- Can be named a differnt way. Another way of saying methylamine is aminomethane

Now that were at the end, here is a condensed video explaining functional groups

may 18 chem 11

Aldehydes

-Double bonded O, single bonded H at the end of a chain
-Naming: change the -e ending to -al
-similar to the ketones, but the oxygen is at the end of the chain

Carboxylic acids

-Found in insect bites
- Building blocks of fats/steroids

Ester

- found in flavoring, perfumes, fruits, vegetables oil etc.
- They are formed by esterfication of carboxylic acids
- Name the primary chain with -yl ending
- Secondary chain ends in -oate

may 14th chem 11

Halides,Alcohols,keytones,Ethers

Today we learned a few new things about naming compounds

Halides

- Halogen atoms replace a hydrogen

- Bromo, Chloro, Floro (bromine, flourine, chlorine)

Alcohols

-just like a normal chain, but with an OH group at the end
- Change the ending to -ol

Ketones

- Oxygen atom double bonded to carbon, with extending carbon chains
- Change the ending to -one

Ethers

- Have an O joining two carbon chains together
- Name each carbon chain with -yl ending and add 'ether' at the end

may 10 chem 11

CYCLO ALKANES

Today we learned about cyclo alkanes, which are basically carbon compounds in ring shapes (they can do that!)
-They still follow the same rules as the rest of the alkanes, but you add "cyclo" to the beginning of the name
- when you are numbering, you can go clock wise or counter clockwise, but start your "1" at the side chain, as you want it to be the smallest number (just like normal)

When a cyclic chain of 6 form, it will create a structure called benzene


Here is a video on naming cycloalkanes

may 3 chem 11

ALKENES

- Compounds with double bonds end in -ene
- Put a # in front of the parent chain that indicates where the double bond is
- Always start from the end with the double bond when numbering the chain
- Any time more than one double bond occurs, you add adi, atri, atetra...
- The longest chain has to include the double bond








<------alkenes naming system

ALKYNES

- For compounds with triple bonds use -yne ending
- Follow all the same alkene rules
- The longest chain has to include the triple bond

This video shows you how to write and name the various chains

april 30 chem 11

Organic Chemistry

Today we started a new unit: organic chemistry, this unit is mostly memorizing and has very little to do with equations themself
- There are more carbon compounds than all ionic compounds combined
- The study of carbon compounds is called organic chemsitry
- Carbon can have multiple bonds and form many different shapes





<-----table of what we will cover Hydrocarbons have three types of formulas:
















1) Molecular formulas
C3H8

2) Condensed Structural Formula
CH3-CH2-CH3

3) Structural Formula

Nomenclature of Hydrocarbons

- One molecular formula can have a number of different structures
- Isomers are compounds that can be drawn in more than one way

ALKANES

1) Name the longest chain by using the correct suffix and adding "ane"
2) Locate any branches by number carbon atoms (use the lowest possible number system)
3) Name branches by using appropriate suffix and -yl ending (Alkyl branches)
4) If there are more than one of the same alkyl group, number each one and add the multiplier number in front of the branch name

april 22 chem 11

Ions in Solutions

- The formation of a solution depends on the ability of the solute to dissolve in the solvent
- Solvation is the interaction between solutes and solvents
- Ionic solids (salts) are cyrstals made up of ions
- Dissolving ionic solutions produces ions in a process called disssociation

Here are 2 examples of ionization

FeCl3 (s) ----->Fe 3+ (aq) + 3 Cl -1 (aq)
(NH4)2SO4 (s) -----> 2NH4 + (aq) + SO4 2- (aq)

april 20 chem 11

Intermolecular bonds (bonds between the molecules)

There are three types of bonds:
-London Dispersion Force (L.D.F)
-Dipole-Dipole
-Hydrogen bonds (H-Bonds)

Here is a short summary of each

1.) LDF

- Results from temporary electron dipoles
- Weakest intermolecular force
- Increases as the # e- increases
- Occurs in any compound that has e-, which is everything

2.) Dipole Dipole



-Results from a permanent dipole in molecules
-Polar molecules experience this force
-Polarity depends on the electronegetivity of the element
- The strength of a dipole- dipole bond depends on the difference in electronegativity between the two atoms

3.) Hydrogen bonds
-This is a special type of dipole- dipole bond between H and O, F, or N
- Any molecule that: H-F, H-O or H-N

april 16th chem 11

POLARITY

Today in class, we learned about the polarity of the many solutes and solvents, we took down the following notes:
-Solutes or Solvents must be either polar or non-polar
-Non-polar substances have equal charge distribution (this means that they are symmetrical)
-Polar substances have an unequal charge distribution (this means that they are NOT symmetrical)



<---- H2O is an example of a non polar solution

The lab's objective was to determine if Glycerin is polar or non-polar.

Here's the background information that was written on the lab:

- Sodium chloride is an ionic solid crystalk that forms a crystal lattice structure. When dissolved in solvents, this lattice breaks up and the ions dissociate.

- Sucrose is table sugar and like Sodium Chloride it also forms a crystal structure. Unlike Sodium Chloride however, Sucrose is not ionic; it is molecular. The structure of Sucrose makes the molecule polar.

- Iodine, like Sucrose, is molecular and also forms crystals. However the crystals of Iondine are non-polar.

- Water is a polar solvent

- Paint thinner is a non-polar solvent

- Glycerine is a polar solvent

The result from this lab was that we learned that like substances dissolve, and unlike do not

Here is a video explaining polar and nonpolar molecules

april 14th chem 11

Solution Conductivity

Today we did a lab about the conductivity of many solutions, including water. We learned that distilled water by itself is not conductive, but tap water is conductive due to the many additional minerals that it contains.


Electrical conduction in solutions requires charged ions to be present.
Ionic solutions dissociate (break apart) when placed in water. Molecular solutions seldom split into ions

The following is the dissociation of Ce2(SO4)3:
Ce2(SO4)3 -> 2 Ce 3+ (aq) + 3 SO4 2+

If the compound is covalent, it will dissociate just into an aqueous version of itself.

We were given a tree to follow to determine conductivity:

Is it a metal?
If yes, then it is CONDUCTIVE. but if no then ask:
Is it a solid non-metal?
If yes, then it is NON-CONDUCTIVE. If no, then ask:
Is it an acid or base?
If yes, than it is CONDICTIVE, if no then ask:
Is it ionic?
If yes, then it is CONDUCTIVE, if no then it is not.

Here is a video about the conductivity of solutions

april 1st Chem 11

CONDUCTIVITY LAB

Today we had a lab and all we really did was tip a conductivity probe into many different solutions to test their various conductivities, we came to the conclusion that ionic solutions are more conductive than molecular solutions.

march 30 chem 11

CHEMISTRY OF SOLUTIONS

Here are a few basic things to know about solution chemistry:
-it is the study of chemical reactions in solutions
-the solution is a homogeneous mixture
-there is a solute and a solvent, solvents are the larger amounts and solutes are the smaller amounts
-a saturated solution contains the optimal amount of solutes
-a unsaturated solution can contain more solute
-solutobility is measured in g/L, g/ml, mol/L


Another major thing to keep in mind is that there are factors that can affect solubility. These include heat, and changing the amount of solvent or solutes.

Water is one of the best solvents because it is polar and is capable of creating hydrogen bonds

Example of a solution: salt water

march 24 Chem 11

BONDING
Covalent Bonding
- Electrons are shared between non-metals
- To draw Lewis Dot Diagrams:\

-Add the valence e- in all atoms
-Identify which atom can form the most number of bonds (this is shown by the pairs that only have 1 electron). This will be the central atom
-Bonds between two atoms are repesented by a line.
-All valence levels must be filled, all electrons must be used

- Some compounds form more than one bond between two elements, they will make double or triple bonds

Atoms V.S ions

- Atoms are electrically neutral
- # of protons = # of electrons
- Ions have a different number of protons and electrons
- Ions can either be positve (lose electrons) or negative (gain electrons)
- Cation = positive ion
- Anion = Negative ion
Here is a video about Atoms V.S Ions










Chemical Bonds - A bond is an electrostatic attraction between particles
- Bonds occur as elements try to achieve Noble gas electron configuration
- Noble gases (usually) do not form compounds or bonds
- In Noble gases the outermost energy levels have stable octets

Lewis Dot Structures - Atoms can be represented by dot diagrams - Dots represent electrons - Only valence electrons are shown - Write the atomic symbol for the atom - This represents the nucleus and filled inner energy levels - One dot is used to represent outer energy levles - One e- is placed in each orbital before any pairing occurs - Beginning with the 5th e-, pairing can occur up to a maximum of 8e- - Below: Electron dot diagrams for water

Ionic Bonds
- Electrons are transferred from metal to non-metal
- No dots are shown on metal
- "Charged" species are written in brackets

Here is a video about how to draw a dot diagram

March 26 chem 11

Electronegativity

- Atoms affinity for electrons
- Electronegativity increase from left to right and from bottom to top
- is is the tendency to attract electrons
-

Here is a video describing electronegativity

March 17 chem 11

Chemical Families and Relationships

The vertical columns in the periodic table are known as groups or chemical families. There are five groups: Alkali Metals, Alkaline Earth Metals, Transition Metals, Halogens and Noble Gases. Hydrogen is actually in a separate group on its own. Elements in the same chemical family have similar physical and chemical properties.

The Alkali Metals make up group 1 of the Periodic Table . Elements in this family are highly reactive and reactivity increases as you go down the group. These metals have only one electron in their outer shell and so,it makes them extremely electropositive. They react readily with non-metals such as oxygen and water, and usually have lower densities than other metals. They also are malleable, ductile, good conductors of heat and electricity and have low melting points. Finally, alkali metals are soft and can actually be cut with a knife.

Elements in the second column make uf the Alkali Earth Metals. They have two electrons in their outer shell and have low electronegativities. They are also less reactive than Alkali Metals but they will burn in air if heated. They will also react with water. They are all metals with a shiny, silvery white colour.

The Transition Metals are the 38 elements in groups 3-12 of the periodic table. They are very hard, have high melting and boiling points, low ionization energies, high electrical conductivity and are malleable, which means that they are able to be shaped and bent.

Halogens make group 17 of the periodic table. They are highly reactive non-metals. However they do not react well with water. Fluorine and chlorine are gases at room temperature, Bromine is a liquid and Iodine and Astatine are solids.

The last family is the Noble gasses, found in group 18 of the Periodic Table. The Noble Gases are the most stable and unreactive elements in the periodic table due to their full valence shells. They are colourless, odourless gases at room temperature. They also have high ionization energies and low boiling points.

Here is a long and boring (but educational) video of the periodic table

March 9 Chem 11

We got a group project assigned today. We are to provide a summary on one of the following topics:

Mendeleev's Periodic Table
Metals
Non-metals
Metalloids
Trends n Physical Properties of Elements on the Periodic Table
Trends in chemical properties of elements on the periodic table (ion charge, chemical reactivity,
ionization energy)
Properties of Alkalis, Alkaline Earth Metals, Halogens, Noble Gases and Transition Metals

The information is to be presented on a poster or powerpoint, and a summary and quiz must come with it

March 5th Chem 11

Friday, March 5, 2010

Today we learned about emission spectra...

-Each element gives off a specific colour of light
- These are known as emission spectra
- they are different to each element
-one of the uses for this is to find out what kind of elements a star is composed of
- If electrons absorb energy they can be bumped to a higher level
- When they fall to a lower level they release that energy as light

Heres a video about the emission spectrum of hydrogen






Atomic Structure

- Atoms are made up of parts called subatomic particles (protons, neutrons and electrons)

here are the details of each subatomic particle:

-A proton has 1 mass, +1 charge, and is in the nucleus
-A neutron has 1 mass, neutral charge, and is in the nucleus
-A electron is 1/1850 mass, -1 charge, and is arranged in energy level around the nucleus

Atomic Number

<------------ the number at the top left corner is the atomic number

- The nymber of protons determine the type of element
Isotopes

- Changing the number of neutrons changes the isotopes of the element
- All isotopes have the same chemical properties

For example carbon 12 has a 12 protons, and 6 neutrons
but as you add another neutron, the weight increases to 13 which gives you carbon 13
the same happens with carbon 14 respectively

Here is a little video about isotopes...

Mass number
-the total number of protons and neutrons

- Symbol given is A

- Different isotopes have different masses

Let's say you're given the Isotope of 12-Ca. The mass would be 12, the atomic number would stay the same as it is given in the periodic table (6), the number of protons would be 6 (same as the atomic number) and the number of neutrons would be 6 (mass number - atomic number).

here is a video about isotopes:

march 1st, Chem 11

today in class we learned about the ATOMIC THEORY
Early Atomic theory

Greeks history of early atomic theory
-In 300 BC, a man named Democritus said atoms were invisible particles, this was the first time the concept of atoms was mentioned

-The problem with this theory was that his theory could not be tested, and it was more of just a model explaining what atoms were thought to be

-Another problem was that there was no mention of the nucleus of any of its constituents

-a third problem was that it couldnt be used to explain chemical reactions, due to the exclusion of valence shell
-somehow, even with all of those problems, his theory was the most veiwed and accepted theory for over 2000 years

,

<------- basic atomic model of democritus

Lavosier (sometime in the late 1700s)

so later on we have the introduction of a man named Lavosier who introduced a few new things:

--Law of conservation of mass

--Law of definited proportions

- his theory was still not correct because it did not show what atoms were, or how they were arranged


Proust (1799)

now we have the indrocuction of proust some few years later, who more or less backed lavosiers laws and said:

-If a compound is broken down into its constituents, the products exist in the same ratio as in the compound (quote,unquote)

Dalton (early 1800s)

so now a few years later we have the introduction of a man lamed dalton, who introduced quite a few new things:

-he stated that atoms are solid, indestructable spheres, and how they relate the different elements

-a few problems were that he didnt mention isotopes, subatomic particles, or a nucleus

<------ the photo of a genious

J.J Thompson (1850)

so about 40-50 years later we get introduced to yet another scientist, J.J Thompson, who introduced quite a few new things

- He was the first man to introduce ( and is most well known for) his raisin bun model
- this basically stated that the nucleus was a solid positive sphere inside a *membrane* and that the atoms were negative particles embedded in the membrane
- he is the first man to introduce a theory involving positive and negative charges, and is also the first man to mention a nucleus
<-------------------------- raisin bun model

Rutherford (1905)

So something like 55 years later we get introduced to another scientist who worked, reworked and of course, introduced new ideas

- He showed that atoms have a dense center with electrons orbiting it (gold foil experiment)

- these results gave him a more planetary model of the atom, which explains why electrons spin around the nucleus

- He also suggests atoms are mostly empty space

- His problem with that method is that the atoms should attract the electrons, making every element extremely reactive
- He also didnt include valence electrons

<-------- Gold foil experiment














Bohr (1920)

15 years later we get introduced to the man that we refer to the most, and use his theory the most:

- He solved rutherfords problem by stating that electrons must exist in specific orbitals around the nucleus
-he also explained how valence electrons were used in atomic bonding
- he also explained the difference between ionic and covalent bonding
- he also includes the neutron

February 1 Chemistry 11

Today in class we learned perecent yield and limiting reactants.

Limiting reactants:
the chemical that gets used up first
one reactant has to be completely consumed for it to be a L.R
this can tell you how much of a product can be produced and how much of a product do you need to fully consume another product
to find the L.R. guess which reactant is the limiting reactant and do the calculations to see if you are correct

Example: What is the limiting reactant when 125g of P4 reacts with 323g of CL2 to form Phosphorous trichloride?

P4 + 6CL2 = 4PCl3
125g x 1 mol / 124g x 6 mol / 1 mol x 71g / 1 mol = 431g of Cl2

Cl2 is the limiting reactant because you only need 125g of P4 to consume 431g of Cl2
L.R. = Cl2

here is a youtube video explaing Limiting Reactant


Percent yield there are two parts to this the actual yield and theoretical yield.
The theoretical yield of a reaction is the expected calculated amount
The experimental amount is the actual yield
The formula to calculate the percent yield is actual yield / theoretical yield x 100

Example
The production of urea CO(NH2)2 is given by:
2NH3 + CO2 = CO(NH2)2 + H2O

If 50g of urea are produced when 1 mol of CO2 reacts, find the acual yield, theoretical yield and percentage yield.

Actual yield: 50g
Theoretical yield: 1 mol CO2 x 1 mol / 1mol x 60.1 g = 60.1g

Percent yield : 50g / 60.1 g x 100 = 83%

Here is a video explaing about percent yield.

January 28 Chemistry 11

Copper Sulfate




Strontium Nitrate









Today in chemistry 11 we did a lab involving the stoichiometric method. We checked to see if the mass of precipitate matches with our prediction.

In this experiment we had to dissolve 2g of strontium nitrate in 50ml of water and then it would react with the left over copper (II) 3g of sulphate. once it reacted the product would be a precipitate. After we mixed the solutions the precipitate would be seperated by filtration, then we would have to leave it in the drying oven and weigh it when it is completely dried. We had to wait 1 day for all of the water to dry to make sure because just a drop of water could give us a huge amount of error in our percentage error.
After we had to calculate the number of moles of precipitate that were formed. We needed to make sure that none of the precipitate was left behind after pouring the mixture into the funnel. This also could give us a huge error towards our percentage error.


The balanced equation for this lab was:
Sr(NO3)2 + CuSO4 = SrSO4 + CU(NO3)2

January 26th Chemistry 11

We continued our lesson on Stoichiometry learning how to convert from mass to mass

Example: Lead (IV) nitrate reacts with 5.0 g of potassium iodied. how many grams of Lead(IV) Nitrate are required?
Pb(NO3) + 4 KI = 4KO3 + PbI4
5g x 1 mol KI/ 165.9g x 1 Pb(NO3)4/4KI x 455.2 / 1mol Pb(NO3)4 = 3.4g

when converting mass to mass it requires one extra you just have to convert the number of moles into grams.

Example: given the reaction 4CH3No2 + 3 O2 = 4 Co2 + 6H2O + 2N2 what mass of H2o is produced when .150g of CH3NO2 is burned?
.150g Ch3No2 x 1 mol Ch3NO2/ 61.0g Ch3NO2 x 6mol H2O / 4mol CH3NO2 x 18.0 g H2O/ 1mol H2O = .0662g

after learning all of this Mr.Doktor taught us Percent Yield
-theoretical yield of a reaction is the quantity or products expected
-the amount produced in an experiment is the actual yield

percent yield formula = Actualy mass of product / Predicted mass of product x 100
you want to get the number closes to 100.

Example:
the production of Urea CO(NH2)2 is given by:
2NH3 + CO2 = CO(NH2)2 + H2O
If 47.7g of Urea are produced determine the theoretical yield of 1 mol of CO2 reacts
1mol CO2 x 1mol CO(NH2)2 / 1mol CO2 = 1mol CO(NH2)2
1mol CO(NH2) x 60.1g / 1mol = 60.1g

b) actual yield
47.7g

c) percent yield calculation

47.7g / 60.1g x 100 = 79%

Here is a video on Perecent Yield:

January 22nd Chemistry 11

In chemistry class today we just learned about more stoichimetry we learned how to convert from mass to moles using volume at STP.

example: When 1.5g of oxygen reacts with nitrogen monoxide how many moles of nitrogen dioxide are produced?
1.5 x 1 mol O2 / 32g x 2 mol NO2/ 1 mol O2 = 0.0094mol of NO2

2)If 2g of O2 reacts with nitrogen monoxide what volume of nitrogen dioxide is present at STP?
2.0g x 1mol O2 / 32g x 2 mol NO2/ 1 mol O2 x 22.4L / 1mol NO2 = 7.8L of NO2

3) in the formation of Copper (II) oxide 3.5g of copper react. How many moles of copper oxide are produced.
3.5g x 1mol Cu/ 63.5g x 2mol CuO/ 2mol Cu = .55mol CuO

January 20 Chemistry 11

Today in chemistry 11 we learned about stoichiometry.
coefficients in balanced equations represents the moles and they are also conversion factors.

remember that when you are solving a question it is always what you need over what you have.

Example: if a .15mole sample of methane reacts with oxygen how many moles of each product is produced?

The balanced equation is : CH4 + 2O2 = CO2 + 2H2O you will always need a balanced equation.

.15 mol CH4 x 1 mol CO2/1 mol CH4 = .15mol CH4

you use the coefficients for the number of moles just remember what you need/what you have

.15mol CH4 x 2mol H2O / 1 mol CH4 = .30 mol of H2O

For further help and problems refer to this website: http://www.shodor.org/unchem/basic/stoic/index.html

January 18 Chemistry 11

Today in chemistry we did a lab on heat of combustion of candle wax. we were to find the heat released when one mole of paraffin wax was burnt.
The materials we used were :
Candle
match
Weighing scale
lab stand
wire triangle
150ml of cold water
Pop can
thermometer

The procedure was:
set up the lab stand and the wired triangle
measure 150ml of water and pour it into the pop can
record the temperature
place the candle under the pop can and light it
let the candle burn for 10 minutes then get the new temperature
clean up after your done

Observations:
volume of water used
initial temperature of water
initial mass of candle
final mass of candle
final temperature of water

with that information we can calculate the mass of the paraffin wax that was burnt during the experiment, the moles of wax that was reacted, the number of joules of energy the water gained and the molar heat of combustion of the paraffin wax.

It was a fun lab that we did today in class just remember safety comes first always keep on your safety goggles and aprons or else you and your group members will lose 10%!

Here is a link similar to the lab we did today in class:
http://www.chalkbored.com/lessons/chemistry-12/calorimetry-candle-lab.pdf

January 14 Chemistry 11

In todays class we learned about calorimetry and molar enthalpy.

Calorimetry: to measure heat absorbed and released by water we have to find out three things:
1) temperature change degrees Celsius
2) amount of water g , kg , ml , L
3) heat capacity kJ/kg ° C the heat needed to change 1 degree in ° C is 1kg

ΔH = mCΔt will be the formula we will need to know.
the heat capacity of water is 4.19 kJ/kg° C

Example: a glass of water 250g is at 20 celsius it is placed on a stove and heated until it reaches a final temperature of 85 clesius, how much energy was added to the water?
m= .250kg change it to kg
c = 4.19
t = 85-20 temperature final - temperature initial
(.250)(4.19)(85-20) = 68.1kJ

Molar Enthalpy: heat absorbed/released by one mole (kJ/mol)

Example:
if there is 1g of wax burnt what is the amount of energy released?
C25H52 + 38O2 = 25CO2 + 26H2O + 11ookJ
convert grams to moles 1g = 1mol/352g molar mass of candle
= .00284mol
then we go .00284mol x 1100kJ / 1molC25H52 = 31.2 kJ/mol
Answer: 31.2 kJ/mol of energy is released when 1g of wax is used

Calirometry video:


Molar Enthapyl video:

January 12 Chemistry 11

In todays class Mr Doktor started out by combing ammonium nitrate and water which made the beaker turn cold. This was an endothermic reaction. After he lighted the bunsen burner and burned magnesium the magnesium turned to light and this was an exothermic reaction. He then burned steel wool and there were sparks which was another example of an exothermic reaction.

We then took notes on heat and enthalpy
reactions that release heat are called exothermic
reactions that absorb heat are endothermic
heat is a form of energy all chemicals have energy stored in them stored energy is called enthalpy
the symbol for enthalpy is H

Exothermic reaction and Endothermic reaction:






To write Exothermic reactions it would be:
2C8H18 + 25O2 = 16CO2 + 18H2O + 5076 KJ
2C8H18 + 25O2 = 16CO2 + 18H2O H = -5076Kf exothermic = negative


For Endothermic it would be:
2C + 2H2 + 52.3 KJ = C2H4 52.3KJ
2C + 2H2 = C2H4 H = 52.3 KJ endothermic = positive

Coefficients can also stand for moles of molecules
N2 + 3H2 = 2NH3 + 46.3 kJ
1mol of N2 = 46.3 kJ
3 mol of H2 = 46.3 kJ
2 mol of NH3 = 46.3 kJ

Example: find the amount of heat produced if 5 mol of H2 are consumed when making ammonia.
46.3 kJ / 3mol H2 x 5 mol of H2 = 77kJ

Here is a video on Endothermic and Exothermic reactions:

January 8 Chemistry 11

In today's class we learned about the 6 types of chemical reactions:
Synthesis
Decomposition
Single Replacement
Double Replacement
Neutralization
Combustion

1) Synthesis: two or more substances that are combined
A+b = C
H2 + Cl2 = 2HCL


2)Decomposition: breaking down a compound to simpler elements
AB = A+B
2KClO3 = 2KCL + 3O2


3)Single Replacement: When the compounds have a metal and a non metal and the metals switch places.
A + BC = B + AC
2AGNO3 + CU = CU(NO3)2 + 2AG


4)Double Replacement : exchange of atoms between two different compounds
AB + CD = AD + CB
AgNO3 + KCL = AgCL + KNO3

5)Neutralization: the products will will be water or salt it usually contains an H and OH in the equation balancing out to water
2NaOH + H2CO3 = Na2CO3 + 2H2o

6)Combustion: reacts with oxygen to form an explosion
C3H8 + 5O2 = 3CO2 + 4H2O


Here is a video describing only 5/6 of the chemical reactions. ( it does not describe neutralization)

January 6 Chemistry 11

In chemistry class today we learned about balancing equations with C H and O. The products are always the same CO2 and H2O.

An Example would be:
C6H12O6 + 6O2 = 6CO2 + 6H2O

After we learned how to use words in our balanced equation.
Example:
Aluminum bromide and chlorine gas react to form aluminum chloride and bromine gas.
2AlBr3 + 3Cl2 = 2ALCL3 + 3Br2
You have to find the symbol for each name Aluminum bromide chlorine etc write the the equation and then balance it accordingly to the number of atoms on each side.

Here is a video helping you to balance word equations:


Mr Doktor also gave us a list of acids that we should memorize:
HCL = Hydrochloric Acid
HNO3 = Nitric Acid
H2SO4 = Sulphuric Acid
H3PO4 = Phosphoric Acid
CH3COOH = Acetic Acid

December 17 Chemistry 11

Today in Chemistry class we learned about balancing equations.

Chemical equations show us the reactants used and the products that are produced during a chemical reaction the numbers in front of the symbols are coefficients which refers to the number of moles.

to balance a chemical equation there must be the same numbers of each atom on both sides of the equation.
Examples :
Al + O2 = Al2O3
C2H6 + O2 = 2CO2 + 3H2O
Fe2O3 + 3H2SO4 = Fe2(SO4)3 + 3H2O

Here is a video showing you how to balance chemical equations:

There are the same number of each type of atom on each side of the equation

December 15 Chemistry 11

Today in Chemistry 11 we started our new unit on chemical reactions Mr.Doktor showed us some chemical reactions today. First he started out by by adding bromothemal blue and hydrochloric acid which turned to a yellow color. Then he added ammonia to the acid and it turned blue. After Mr Doktor mixed potassium iodide with iron iodide and it made the solution turn yellow. Mr.Doktor then showed us another chemical reaction by burning a strip of magnesium which made a very bright light and he told us this is how they started fire works. His last chemical reaction was he dipped ap iece of paper in alcohol and lit the paper on fire, the paper did not set on fire at all but instead the alcohol was burning.