At the previous class of the mole conversion, we've learnt:
-From particles → moles.
-From moles → particles/molecules/formula units/atoms
-From moles → grams
-From grams → moles
The previous sections showed how to perform single-step conversions between moles and any of mass, volume, or number of particles. This section shows how to convert between mass and volume, number of particles and mass, and so on. The box table below summarizes the conversion factors needed.
Conversion | Conversion Factor
6.022x10^23 particles
-mole → particles | 1 mole
______________________________________________________
-mole → mass | molar mass g
1mol
______________________________________________________
-mole → volume | 22.4 L
1 mol
______________________________________________________
-molecules → atoms | # atoms
1 molecule
Wednesday, November 24, 2010
Friday, November 19, 2010
Mole Conversions
There are two main types of mole conversions:
Let's see some Grams to Moles Conversion
- Gram to Mole Conversion
- Mole to Gram Conversion
- Particles to moles Conversion
- Moles to Particles Conversion
Let's see some Grams to Moles Conversion
Moles to Grams Conversions:
Conversions between particles and moles:
More information about Mole Conversions:
Thursday, November 18, 2010
Chapter 4 Moles
Chapter 4 Moles
What is a mole?
A mole is a number, just like a dozen is the number 12. However the mole number is called the Advagadro's number which is about 6.022*10^23.
Why do is mole so important in Chemistry?
-Acording to Avogadro's Hypotheses, Gas with equal volume at same temperature and pressure will have the same number of particles.
 |
| Avogradro and his mole number! |
What is a mole?
A mole is a number, just like a dozen is the number 12. However the mole number is called the Advagadro's number which is about 6.022*10^23.
Why do is mole so important in Chemistry?
-Acording to Avogadro's Hypotheses, Gas with equal volume at same temperature and pressure will have the same number of particles.
 |
Tuesday, November 9, 2010
Review: Chapter 3
Significant Figures:
-measured or meaningful digits.
-can be precisedif there are many of them.
e.g 24.37 24.6
Accuracy:
-It is how close the measurement (or average measurement) comes to the accepted or real value.
Precision:
-It is how reproducible a measurement is compare to other similar measurements.
Absolute Uncertainty:
-the uncertainty expressed in the units of measurement, not as a ratio.
Relative Uncertainty:
-Relative Uncertainty = Absolute Uncertainty
———————————
Estimated Measurement
Density:
-defined as its mass per unit volume.
-formula of density: Mass
D = ————
Volume
-measured or meaningful digits.
-can be precisedif there are many of them.
e.g 24.37 24.6
Accuracy:
-It is how close the measurement (or average measurement) comes to the accepted or real value.
Precision:
-It is how reproducible a measurement is compare to other similar measurements.
Absolute Uncertainty:
-the uncertainty expressed in the units of measurement, not as a ratio.
Relative Uncertainty:
-Relative Uncertainty = Absolute Uncertainty
———————————
Estimated Measurement
Density:
-defined as its mass per unit volume.
-formula of density: Mass
D = ————
Volume
Saturday, November 6, 2010
Lab 2E Quiz and Graphing
Today we have just done a quiz on Lab 2E.
The quiz was just all about calculating the thickness of a certain object, such as alunminum foil.
Equation:
Density=Mass/Volume
If you want to calculation the thickness based on the information of an object:
Density=2.70g/cm^3
Mass=5.0g
The object Area=15cm by 16cm
And calculation the thickness:
It goes,
Volume=(2.70g/cm^3)/5.0g=0.54m^3
Thickness=0.54cm^3/15cm/16cm=2.25*10^-3cm
The quiz was just all about calculating the thickness of a certain object, such as alunminum foil.
Equation:
Density=Mass/Volume
If you want to calculation the thickness based on the information of an object:
Density=2.70g/cm^3
Mass=5.0g
The object Area=15cm by 16cm
And calculation the thickness:
It goes,
Volume=(2.70g/cm^3)/5.0g=0.54m^3
Thickness=0.54cm^3/15cm/16cm=2.25*10^-3cm
Next, we went to lab room and learnt how to graph base on the information of mass and volume.
Thursday, November 4, 2010
Lab 2 E
Today in class, we had an exciting lab on determining the thickness(height) of the aluminum foil.The lab was to help us get more familiar with sig figs, accuracy, precision, uncertainties and the formula of density. Thus we all enjoy this super amazing lab!!!
Purpose: Find accurate and precise measurement of the thickness of the aluminnum foil expressed using correct number of sig figs.
Procedure
Purpose: Find accurate and precise measurement of the thickness of the aluminnum foil expressed using correct number of sig figs.
Procedure
1. We start off by measureing all measuring the length and width of foil that is at least 15 cm on each side
2. Than we use the centigram to measure the mass of each foil.
3. After we calculated the Mass we than use the density formula to calculate the volume of the foil.
4. When we finished calculating the volume of the aluminum foil, we than use the lengh and width to calculate
the height because LxWxH=V
eg.V=0.36cm^3
L=15.60cm
W=15.35cm
Hight=0.36cm^3
--------------
15.60cm*15.35cm
=1.5*10^-3(Remember round you sig figs till the very end!!)
5. The final step is for us to calculate the experimental error when it comes to the accepted value for thickness of the aluminum foil which Mr.Chen gave us was 1.55*10^-3.
Formula Expremental error:
Experimental error=Your measurement-Accepted value
---------------------------------------------
accepted value *100
6.At the end of the experiment we wrote a conclusion on how accurate and precise
our messurement was. Our measurement was precise because our experimental error
was only 3.2%. It was also precise because we got almost the same value each
time when we calcute the thickness of the foil for 3 trials.
Need more help go to: http://www.mefeedia.com/watch/29045208
Note:Quiz next class on everything we done today on the lab !!!!
Tuesday, November 2, 2010
Density
Density:
-defined as its mass per unit volume.
-or, its weight per unit volume.
-Osmium is the most densest known substance at standard conditions for temperature and pressure.
-less dense fluids float on more dense fluids if THE FLUIDS DO NOT MIX.
Here is an example of density between fluids.
-formula of density: Mass
D = ————
Volume
Example: An iron bar has a mass of 12.00 g and a volume of 1.25 L. What is the iron bars density?
As we know D=M/G, we could simply plug in the number, D=12.00g/1.25L which equals to 960 but don't forget the units! Its 960 g/L.
-defined as its mass per unit volume.
-or, its weight per unit volume.
-Osmium is the most densest known substance at standard conditions for temperature and pressure.
-less dense fluids float on more dense fluids if THE FLUIDS DO NOT MIX.
Here is an example of density between fluids.
-formula of density: Mass
D = ————
Volume
Example: An iron bar has a mass of 12.00 g and a volume of 1.25 L. What is the iron bars density?
As we know D=M/G, we could simply plug in the number, D=12.00g/1.25L which equals to 960 but don't forget the units! Its 960 g/L.
Leif Tung
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