Tuesday, October 27, 2009

OCTOBER 26, 2009 [JOANNE]

GASES AND MOLES:

The volume of a balloon occupied by a certain gas depends on the temperature & pressure.

Standard Ambient Temperature & Pressure (SATP)

  • 24.8L / 1mol
  • 25°C and 100kPa

*We will focusing much on SATP yet

STP:

The molar volume of any gas at STP is 22.4L

  • 22.4L / 1 mol
  • 1 mol / 22.4L

EXAMPLES:

Ø Find the volume occupied by 0.060 mol of c02 at STP
0.060mole x 22.4L/1mole = 1.3L

Ø Find the mass of a 200.0 mL sample of NO2 at SATP
STEPS:

o Note that the 200.0mL given is not in L

o Before we can convert it by SATP, we must change the mL to L.

o We divide 200.0mL by 1000 for our conversion factor from mL to L.

o Then we use SATP (22.4L / 1 mol )

o To finish the question in grams, we multiply by 46.0g because N = 14.0g + !6.0(2) O = 46.0g

o The Equation:

§ 200.0mL x 1L/1000mL x 1mol/22.4L x 46 g/ 1 mole = 9200/22400 =.41g

Ø Find the volume occupied by 22.0g of CO2(g)

o 22.0g x 1mol / 44.0g x 22.4L / 1mol = 11.2 L

Oct. 21st /2009 [THE Christian Bondoc]

Herro.

Atomic Mass
  • The mass of 1 mole of atoms in an element
  • The mass of 1.0 mol of 'C' atoms is 12.0g
  • The mass of 1.0mol of 'Ca' atoms 40.1g.
Molecular Mass
  • The mass of 1.0 mole of molecules of an element or compound
N2, O2, H2, Br2, Cl2, F2, I2, P4, S8
  • Assume the all the rest are monoatomic
(I apologize for the size, when i made it large, part of it got cut off)
Finding the molar mass of compounds
H2O
2 H = 2(1.0) = 2.0
1 O = 1(16.0) = 16.0
18.0g/mol
Find the molar of ammonium phosphate
NH4+
PO4 3-
(NH4)3PO4
3 N = 3(14.0) = 42
12H = 12(1.0) = 12
1P = 1(31.0) = 31
4O = 4(16.0) = 64
149g/mol

Converting mass <----> Moles
Conversion factor g/mol or mol/g
Find the mass of 2.5mols of water
H20 -> 18.0g/mol

(1mol/18.0g) x (1/2.5mol)
(1 mol/18.0g) x (1/2.5mol)
= 1/45g
= 45g
Find the number of moles in a 391g samples of nitrogen dioxide

NO2
1N = 14(1.0) = 14
2O = 2(16.0) = 32
45g/mol
(391g / mol ) (1 / g) =
(391g / mol) (1/ g) =
(391/mol) (1/46) = 8.5mol

1) Find the mass of 2.5 moles of water.
2H: (2)(1)
1O: (1)(16)
= 18g/mol

2.5 mol • 18.0g /mol= 45g

2) Find the number of moles in a 391g sample of nitrogen dioxide.
1N: (1)(14)
3O: (3)(16)
=45g/mol

391g • 1mol/45g = 8.5 mol

3) 3.6kg of sulphur trioxide = ? mol
11S: (1)(32.1)
3O: (3)(16.0)
= 80.1 g/mol

3.6kg • 1000kg/1g = 3600 g
3600g • 1mol/80.1g = 45mol

Friday, October 23, 2009

October 19, 2009 [JOANNE]


THE MOLE:

1 mole = 6.02 x1023 -- Avogardo's Number

HYDROGEN BOMB EQUATION:
2H2 + O2 = 2H2O

(2H2 molecules 1 O2molecule 2 molecules of H2O)

12,02 x 1023 of H2 molecules + 6.02 x 1023 molecules of O2 = 12.04 x 1023 molecules of water
-> 2 mole of H2, 1 mol of O2, 2 mol of water

HOW GASES COMBINE
- John Dalton
- Look at masses of gases

(Ex.) 11.1g of H2 reacts with 88.9g of O2
(Ex.) 46.7g of N2 reacts with 53.3g of O2
(Ex.) 42.9g of C reacts with 57.1g of O2

JOSEPH GAY-LUSSAC:
- combine gases based on volume
Ex.) 1L of H2 reacts with 1L of Cl2 = 2L of HCl
Ex.) 1L of N2 reacts with 3L of H2 = 2L NH3
Ex.) 2L of CO reacts with 1L of O2 = 2L CO2
**gases combine in simple whole # ratios


AVAGARDO'S NUMBER

- Equal volumes of any gas at a constant temperature and pressure contain equal number of molecules

OCTOBER 15, 2009 [JOANNE]

We had our chapter 2 nomenclature test.

//.
Here is a random picture of a periodic table tattooed onto an arm!! :)


Friday, October 16, 2009

OCTOBER 13, 2009 [JOANNE]

Today we did an experiment in class.
We started by measuring the weight of a solid hydrate, which was a red colour. We then placed it in a test tube and heated it with a bunsun burner until the hydrate inside melted into a light blue liquid colour.
Our percentage error was 11%

NEXT CLASS:
Test!

-Joanne H.

Sunday, October 11, 2009

OCTOBER 8, 2009 [JOANNE]

Today, Mr Doktor showed the class how to use a bunsun burner. He went over some basic safety rules and told us to always inspect the hose before using it and to never leave the gas on.
When he turned off the classroom lights, the bunsun burner emited a blue flame.

Mr. Doktor also did an experiment in class where he mixed sulfuric acid with sugar.

Classmates were complaining about the concentrated smell of burning sugar!

ACIDS
-Solid, liquid, or gas at SATP (standard ambient temp & pressure)
-form conducting aqueous solutions
-dissolve in water to produce H+
-taste sour
BASES
-turn red litmus blue
-slippery
-nonconductive
-dissolve in water to produce OH-
NAMING ACIDS
~acids are aqueous (dissolved in water)
~hydrogen compounds are acids
-HCI(aq)-->Hydrochloric acid
-H(2)SO(4)(aq)-->sulfuric acid
~Hydrogen appears first in the formula unless it is part of a polyatomic group
~CH(3)COOH(aq)-->acetic acid

HI(aq)--> Hydro Iodic Acid
-classical rules use the suffix IC and/or the prefix HYDRO-

sulfuric acid
hydrochloric acid
~IUPAC system uses the aqueous hydrogen compound

HCI(aq)Aqueous hydrogen chloride

NAMING BASES
~for now, all bases will be aqueous solutions of ionic hydroxides
-NaOH
-Ba(OH)2
~use the cation name followed by hydroxide
-sodium hydroxide
-barium hydroxide

these are some examples we went over in class
-H(3)PO(4)(aq) Phosphoric acid
-HNO(3)(aq) Nitric acid
-HNO(aq) Nitrous acid
-Mg(aq) Magnesium hydroxide
-HBr(aq) Hydrobromic acid
-HOOCCOOH(aq) Oxalic acid

HOMEWORK:
Read over lab

OCTOBER 6, 2009 [ROXANNE]

Today in class, we learnt about naming hydrates and their prefixes.
  • copper sulfate & sodium sulfate --> without water the compound is often preceded as 'anhydrous'
    -these crystals contain water inside them which can be released by heating

TO NAME HYDRATES:

  • write the name of the chemical formula
  • add a prefix indicating the number of water molecules
    1-mono
    2-di
    3-tri
    4-tetra
    5-penta
    6-hexa
    7-septa
    8-octa
    9-nona
    10-deca

Examples:

Name the following compounds:

  1. Cu(SO4) - 5H2O ---> copper (2) PENTAhydrate
  2. Li(ClO4) - 3H2O ---> Lithium perchlorate - TRIhydrate
  3. what is the chemical formula of Nickel(2)sulfate hexahydrate?
    Ni(SO4) - 6H2O

MOLECULAR COMPOUNDS

  • composted of 2 or more non-metals
  • low melting point and boiling point
  • share (not exchange) electrons
  • usually end in 'gen' (hydroGEN, oxyGEN, nitroGEN)
  • 7 molecules are DIATOMIC - 2 of the same elements
    -H2, N2, O2, F, Cl2, Br2,I2
  • P4, S8 --> Polyatomic
  • water - H2O
  • hydrogen peroxide - H2O2
  • ammonia - NH3
  • glucose - C6H12O6
  • sucrose - C12H22O11
    *KNOW THE FIRST FIVE!!!!!*
  • methane - CH4
  • propane - C3H8
  • octane - C8H18
  • methanol - CH3OH
  • ethanol - C2H5OH
  • ethane - C2H6

Saturday, October 10, 2009

OCTOBER 2, 2009 [CHRISTIAN]

SEPARATING MIXTURES
Heterogeneous Mixtures: (done by hand)
  • filtration

  • distillation:

  • crystallization

  • chromatography
    *All are physical changes

REVIEW OF ATOMS

  1. matter is made up of atoms

  2. molecules are groups of atoms held together by electrical bonds

  3. ions are atoms or molecules that have an electric charge
    -positive ions are cations
    -negative ions are anions

  4. atoms are made up of 3-subatomic particles

  5. Protons:
    -positive charges
    -inside nucleus
    -each element has a different number of protons
    -protons = atomic number

  6. Neutrons:
    -neutral
    -inside nucleus
    -nearly same mass as protons
    -adding or removing neutrons does not change the element

  7. Electrons:
    -negatively charged
    -located outside the nucleus
    -1800 times smaller than protons
    -chemical reactions occur between electrons in different atoms/compounds

PROPERTIES OF THE PERIODIC TABLE

  • FAMILIES(or groups) form vertical columns
    -all elements of a family have similar traits and characteristics

  • PERIODS are horizontal rows. Elements gradually chane from metals to non-metals as you move from left to right

ELEMENTAL INFORMATION

  • exceptions are:
    copper - cuprum
    gold - aurum
    iron - ferrum
    lead - plumbum
    silver - argentum

  • first letter is always CAPITAL

  • second letter is always LOWER CASE

CHEMICAL NOMENCLATURE

  • naming chemical compounds has been a very difficult task and different systems have been used through the centuries

  • today the most common system in IUPAC for most chemicals
    -ions
    -binary ionic
    -polyatomic ions
    -molecular compounds
    -acids

CHEMICAL FORMULAS

  • be aware of the differences between ion and compound formulas
    - Zn^2+ (2+ is the ion charge)
    -BaCl2 (the 2 is lower)(number of ions)

NAMING IONS

  • for metals use the name of the element and add ion
    -Al^3+ = aluminum ion

  • for non-metals, remove the original ending and add "-ide"
    -F- = Fluorine becomes Fluoride

  • polyatomic ions have special names

BINARY IONIC COMPOUNDS

  • ionic compounds contain two elements - one metal and one non-metal

  • metallic and non-metallic ions bond together

  • election is transferred from the metal to the non-metal

  • net charge must be zero - total positive charge - total negative charge

NAMING BINARY IONIC COMPOUNDS

  • metal name + first part of non-metal "-ide"

STEPS

  • write formula

  • criss-cross charges

  • reduce ion numbers to lowest common multiples

SEPT 28 + 30, 2009 [JOANNE]

SEPTEMBER 28, 2009

Today we watched a video.
The class was to identify any chemical / physical changes shown in the video.
________________________
PAGE 73: SECTION REVIEW 2-3
_________________________

LAW OF CONSERVATION OF MATTER:
- Matter can neither be created nor destroyed

A. CLASSIFICATION OF MATTER

  • We can divide matter into two types:
    • Homogeneous Substances
    • Heterogeneous Substances
  • HOMOGENEOUS: consists of only one visible component
    -distilled water, oxygen, graphite

  • HETEROGENEOUS: contain more than one visible component
    -chocolate chip cookie, granite

B. PURE SUBSTANCES

there are two types of pure substances:
-Elements: substances cannot be broken down into simpler substances by chemical reactions (oxygen, iron, magnesium)
-Compounds: substances that are made up of two or more elements and can be changed into elements (or other compounds) by chemical reactions (water, chocolate chips, sugar)




FOUR STATES OF MATTER:

STATE:

EXAMPLE:

CHARACTERISTICS:

1.) SOLID Gold - High density


- Density little affected by pressure

- Holds its own shape in a container

2.) LIQUID Water - High density + little affected by pressure


- Adopts shape of its container

3.) GAS Nitogen - Low density


- Density depends on pressure

- Expands to fill its container

4.) PLASMA Interior of the sun - Density depends on pressure


- Expands to fill its container

- Exists only at high temperature

CHEMICAL PROPERTIES
-Substance cannot be observed without altering the substance
- Ex. Flammability

CHEMICAL CHANGES:
Ex.// wood burning, food cooking, rust

PHYSICAL PROPERTIES
-Substance can be observed without altering the identity of the substance
Ex.// Density, colour, melting point

PHYSICAL CHANGES:
Ex.// crushing, tearing

_________________________________

SEPTEMBER 30, 2009



ELEMENT:
-Substance can not be separated into simpler substances

COMPOUND:
- Two or more elements combined together in a chemical reaction

ELECTROLYSIS: - "to tear apart with electricity"
-An electric current passes through a substance. If the substance is a compound, it will split into two or more elements
Ex.// Waster ---> Hydogen + Water

Elements and compounds are pure substances because it has a unique set of chemical and physical properties.

Posted by: Joanne

SEPT 17, 2009 - Unit Conversions review / Salt water lab [CHRISTIAN]

Class started out, with a review on unit conversions, giving us a few examples on the board.

Examples:

1. Change 120kg into mg.

(120kg/1)(1000g/1kg)

(120kg)(1000g/1kg)

= 120 000 000mg(in SD: 1.2×10^8)

2. 7.25 L/S into mL/min

(7.25L/S)(60 S/min)(1000mL/L)

(7.25L/S)(60 S/min)(1000mL/L)

(7.25/s)(60 /min)(1000mL)
= 435000mL/min(SD: 4.35×10^5)

3. 174kg/s into Mg /h

(174kg/s) (3600s/h)(MG/1000kg)

(174kg/s)(3600s/h)(MG/1000kg)

(174)(3600)(MG/1000)
= 626.4 Mg/h

Lab:
The experiment consisted of salt, and water, and to figure out what is the maximum amount of table salk you candissolve in 200mL of water(Although wec hanged the volume of water)

The lab was to figure out the amount of salt that can be a volume of water. First trial was with 10mLs, 2nd trail was with 20mLs, 3rd was with 30mLs and the last, and 4th trail was with using 40mL. Then the groups were suppose add salt slowly and stir, while using the electronic scale until salt cannot be mixed anymore and you could see bits of salt floating in the water. At that point, you minus the previous weight with the current weight, and you get the mass of salt. Groups were suppose to do that with 4 trials and draw out a graph, and using that graph make a line of best fit. And using that line of best fit, take an educated guess at the amount of salt 200mL of water can hold.

Posted By: Christian B

SEPT 15, 2009 [ROXANNE]

Significant Figures and 0’s

Two tutorials on significant figures two supplement the “Significant Figures and 0’s” section of these notes.
[youtube=http://www.youtube.com/watch?v=5UjwJ9PIUvE&feature=related]
[youtube=http://www.youtube.com/watch?v=PNH7_nDE6SQ]

For a more in-depth explanation of “Significant Figures and 0’s” http://en.wikipedia.org/wiki/Significant_figures#Identifying_significant_digits is a good resource.

► All digits from 1 – 9 are significant, no matter where they are in a number.
► Zeroes between the digits 1 – 9 are significant.
→e.g. 3009 has 4 sig digs 140012 has 6 sig digs
► “Leading zeroes” (zeroes in front of a number) are not significant. They are “place holders”.
→e.g. 0.00231 has 3 sig digs 0.1003 has 4 sig digs
► If there is NO decimal point in the number, then trailing zeroes (zeroes at the end of a number) are not significant.
→e.g. 100 has only 1 sig dig 45300 has 3 sig digs
► If there IS a decimal point in the number, then trailing zeroes (zeroes at the end of a number) are significant.
→e.g. 103.00 has 5 sigs digs 0.02480 has 4 sig digs 250. has 3 sig digs

Concerning Calculators:
►Do not round with your calculator
→Round your answer only once
→Round only to the correct number of significant digits
►Do not use ^ on your calc, it does not recognize the order of operations in all cases
►Buttons used for scientific notation in your calc can go by these names: EXP, EE, x10, S.N.

Expressing Error
►Error is a fundamental part of science
►you need to have a way to tell in which cases an error is and is not important
e.g. If you are 80cm off measuring a person’s height it makes a big difference, but not when you are 80cm off when measuring the distance from Vancouver to Kamloops
►There are usually 3 reasons for error
→Physical errors in the measuring device (the device is not accurate)
→Sloppy measuring (you can avoid this one with care)
→Changing ambient conditions
→→e.g. This means the measuring device is altered(such as a metal meter stick because they expand or contract in different temps)
►Error is taken to be half the smallest division on your measuring device

Calculated Errors
►There are two different possibilities:
1.Absolute error
2.Percentage error

Absolute Errror
►This is how off you are from the actual answer
ex.50km off from 400k to Kamloops
►Equation: absolute error= measured-accepted
►positive number means your over the accepted value
►negative means your under the accepted value

►Accepted value can also be your predicted value
►Percentage error is used to measure to determine the importance of the difference

Percent Error
(Song video to remember the equation)
[youtube=http://www.youtube.com/watch?v=DmB5ZuYhFmE&feature=related]
►Most common mistakes are made here
►Equation:
Percent error= absolute error/ accepted value
►Equation an a calculator:
%error= ([measured-accepted]/accepted)x100
%error= ([observed-theoretical]/theoretical)x100
►The “( )” in the equations above represent absolute value(even if answer is negative it can be switched to a positive)

Practice/Example Question:
You measure the weight of an orange to be 15n. the actual weight is 17.5 N, what is the % difference? Round to the nearest tenth.
ANSWER
-14.28%>round to>14.30%
Process

Dimensional Analysis
want to know what 100km/h is in miles/hour? Read these notes!
►Conversion rates help us find this out, they never change unlike currency
► Just like converting between currencies in chemistry it is usually necessary to convert between units
►This process is called dimensional analysis

STEPS
1. Find a unit equality
2. Find the conversion factors
3. Apply conversion factors
4. Cancel units
►You can skip 1,2,3 as long as 4 is correct

Practice/Example Question:
How many miles are there in 120km?
1.[unit equality] 1mi=1.6km
2.[conversion factor] 1=(1mi/1.6km)
3.[apply the conversion factor] (120km)(1mi/1.6km)
4.[cancel units] (120)(1/1.6)
[answer] 75

Sept 11, 2009 [JOANNE]

Todays class we got 2 handouts: a picture of the periodic table (have not yet discussed) and a picture of some whimis symbols for lab safety. We are expected learn and memorize them because it will be on the chapter test.

Whmis Symbols

____________________________________________________________________________________________

Class Notes:

MEASUREMENT AND CHEMISTRY:

  • In Scientific Method, accurate measurements are essential.
  • The most common system in use today is the SI system.
  • The metric system started about 300 years ago in France.

7 FUNDAMENTAL UNITS:

  1. Mass (kg) - Kilograms
  2. Distance (m) - Meters
  3. Time (s) - Seconds
  4. Temperature (mol) - Billions
  5. Amount (K) - Kelvin
  6. Current (A) - Amps
  7. Luminosity (cd) - Candela

PREFIXES & SI UNITS:

Meter ---> Kilometers
1000m -> 1km

1 ---------> m

10^1 = (da) m
10^2 = (h)m
10^3 = (k)m
10^6 = (M)m
10^9 = (G)m

0.1m------------------> 10^-1 dm
0.01- 10^-2 = cm
0.001- 10^-3 = mm
0.0000001- 10^-6 = um - micro
0.00000000001- 10^-9 nm - nano
0.0000000000001- 10^-12 (p)m - pico

SIGNIFICANT DIGITS:

  1. Digits 1-9 are always significant
  2. Zeros are significant if they are right of a decimal.
    • Example: 2.010 - significant
      0.002 - insignificant

_____

CLASS HOMEWORK:

Practice questions #7-8 Page 30 and Page 33 #9-10

September 9, 2009

Today we learned about lab safety and scientific method.

Scientific method goes by this flowchart
Observation-> Question-> Hypothesis-> Design experiment-> Test it-> Conclusion

If the results are different then simply design a different experiment for the next question, if the answer is correct redo the experiment to see if the answers are consistent.

For lab safety the most important rules are:
- No horse play
-listen to instructions
-wear safety gear
-don’t eat/drink in the lab
- be aware of where the safety equipment is (ex. eye wash)
----
Class HW:
PG 14-15 read
Do questions 1-3 on pg 15

-Roxanne.S-

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