ATOMS & MOLECULES

1. for monoatomic elements
a molecule= an atom

2. diatomic elements:
a molecule an atom
Cl2 Cl

Molecules of compounds:
2 hydrogen atoms}
1 oxygen atom } 1 molecule

EXAMPLE:
write the formula for ammonium carbonate:
(NH4)2 CO3
2-N
8-H
1-C
3-O
= 14 atoms

moles<--->molecules
6.02x10^23 molecules
---------------------
1 mol

**HOW MANY MOLECULES ARE IN A 0.25MOL SAMPLE OF CO2?
0.25<----> molecules
0.25molx 6.02x10^23molecules= 1.51x 10^23 molecules
----------
1 mol

1.51x10^23 carbon atoms
3.02x10^23 oxygen atoms

**5.1772x10^24 molecules of water= ??? moles
5.1772x10^24 x1mol}
------------------}= 8.6mol
6.02x10^23}

OCTOBER 27

Today in Chemistry 11 we did a lab :) YAAAY
we did a lab to determine the ratio of moles of iron consumed to copper produced during the chemical reaction between iron and copper (II) chloride.

We used Nails and blue copper sulphate solution! this is how it went



Homework: Finish the lab (questions)

OCTOBER 22

For today's class Mr.doktor went around the class and checked our unit 2 homework questions. After he took up some questions from the homework sheet.

Gases and Moles
The volume occupied by a certain gas depends on the temperature and pressure.

Standard Temperature and Pressure
T=0 degrees Celsius
P=l01.3 kPa

SATP
T=25 degrees celsius
P=100kPa

The volume of any gas at STP is 22.4L for every mole
22.4 L/1mole OR 1mole/22.4L

Some examples for use of STP
Find the volume (l) occupied by 0.060 mol of c02 at STP
0.060mole x 22.4L/1mole = 1.3L

Find the mass of a 200.0 mL sample of NO2 at SATP
mL -> L -> mol -> g
200.0mL x 1L/1000mL x 1mol/22.4L x 46 g/ 1 mole = 9200/22400 =.41g

• Times the top and bottoms then divide

HOMEWORK: Mole ratio lab -> do up to summary of procedure

Questions from 5-10 on the unit 2 homework questions

OCTOBER 20

To start off class and continue our talk about moles Mr.doktor showed a clip from the Austin powers 3 movie.


Atomic Mass
-The mass of 1 mole of atoms of an element
The mass of 1 mole of "c" atom is 12.01g
The mass of 1 mole of "ca" atom is 40.1g

Molar mass
The mass if grams of 1 mole of molecules of an element or compound is the molar mass

Diatomic numbers
H2, O2, N2, Cl2, Br2, I2, F2

Polyatomic numbers
P4,S8

We did a chart to give us some practice how molar mass is calculated.
Element Symbol Formula Atomic mass Molar mass
Bromine Br Br2 79.9 159.8
Neon Ne Ne 20.2 20.2
Silicon Si Si 28.1 28.1
Hydrogen H H2 1 2
Iron Fe Fe 55.8 55.8

To find the molar mass it is basically like this
Equation - >Ca(NO3)2
1.find out how many elements their are in the equation
Ca=1
N=2
O=6
2.Look on the periodic table and get the atomic mass of the element and times it by how many elements their are in the equation then add
Ca=1x40.1 -> 40.1
N=2x14 - > 28
O=6x16 - > 96
40.1 + 28 + 96 = 164.1g/mol

We also learnt how to convert grams to moles and moles to grams.
Mr.Doktor also mentioned that for how air balloons it is filled with helium instead of hydrogen.If hydrogen is used instead the balloon will burst when coming close to fire.

HOMEWORK:

Unit 2 homework questions # 1-4

OCTOBER 16

Today we started chapter 3, The Mole.

One mole = 602 000 000 000 000 000 000 000
or also written as: 6.02 x 10^23 <-Avogadro's Number

2H2 + O2 --> 2H20

How big is Avogadro's number?

• distance from earth to the moon: 3.84 x 10^5 km
• distance from earth to pluto: 6 x 10^9 km

How gases combine:

1. John Dalton

• looked at the masses or gases:
  -11.1g of H2 reacts with 88.9g of O2
  -46.7g of N2 reacts with 53.3g of O2
  -42.9g of C reacts with 57.1g of O2
• *No pattern*

2. Joseph Gay-Lussac

• 1L of hydrogen reacts with 1L of Cl2 -> 2L of HCl
  1L of N2 reacts with 3L of H2 0> 2L NH3
  2L of CO reacts with 1L of O2 -> 2L of CO2
• reactions occur in simple rations

3. Avogadro's Hypothesis:

• Equal volumes of any gas at the same temperature and pressure contain equal numbers of molecules

H2 + O2 -> H2O

*Our homework for today is: numbers 1, 2, 3, and 5 on page 322*

OCTOBER 14, 2009

Today's chemistry block went by quickly, we had our unit 2 test that covered nomenclature, the different types of seperation of mixtures & a chart on matter. This took up all our time in class, but we were assigned homework.- read page 313-319.

October 9,2009

Today in class we did a lab where we had to turn a solid into a liquid. During the process, we had to evaporate the water and record the weight of it before and after.When it was a solid, the substance was red and had a crystal look. While turning it to a liquid, the colour changed from red to blue then light blue.