25th November, 2010
Well Hi there~~
Today,,,,, we just finished our quiz on mole conversions,,,,,, sooooo,, actually,,
WE DIDN"T LEARN ANY NEW THING TODAY!!! =[
Anyways,,,,, I think doing a revision about mole conversions here would be better before we start on something new~~
So here,,,,
Converting gram to mole is : x1mole/MMg
Moles to particles: x 6.022x10^23/1 mole
Particles to #atoms in particle: x #of atoms/1 molecule
P.S> don't forget to that we have homework.
the two worksheets: The wonderful world of mole
Harder mole conversions!
Have a fun weekend. =]
Friday, November 26, 2010
Tuesday, November 23, 2010
THE HOLY MOLY CONVERSIONS~
HOLY MOLY! now, we are talking about Harder Mole Conversions...
Well, they aren't necessarily much harder. If you master the basic stuff, this should be easy!
One thing you HAVE to keep in memory is THIS: MOLE MAP!-> you will never get lost with it!
Now, recall that MOLE is defined as the amount of substance that contains 6.022 X 10^23 atoms or molecules or subatomic particles. This numeric value 6.022 X 10^23 is also called as Avogadro's number.
So, a mole of any substance (atom or molecule) would be equal to the atomic mass/ molecular mass of that substance in gram.
Steps to be followed:
1) Find the molar mass of element
2) Conversion of mass ( 80g ) into moles.
3) Getting the multiplication of obtained moles by avogadro's number to get the number of atoms.
Since we Know that
Atomic mass of Ca= 40 g/mole
so, the number of moles in 80g of Ca = given mass / atomic mass
= 80g / 40 g/mol = 2 moles
Here we got the 2 moles of Ca from 80g of Ca.
Now, 1 mole of Ca = 6.022 x 10^23 atoms of Ca ( By definition )
Therefore, 2 moles of Ca = 2 X 6.022 X 10^23 atoms
= 1.204 X 10^24 atoms of Ca
Thus, we got that
80g of calcium contains 1.204 X 10^24 atoms of the substance Ca.
Steps to be followed:
1) Find the molecular mass of substance ( here, 40g / mole)
2) Find the moles of this mass
3) convert this moles into number of molecules of substance
4) get the individual number of constituent elementary atoms
Here we know the molar mass of NaOH= 40 g/mole
So, the no. of moles in 80g of NaOH = 80g/ 40 g/mole
= 2 moles
Now, since 1 mole of NaOH = 6.022 X 10^23 molecules of NaOH
So, 2 moles of NaOH = 2* 6.022 x 10^23 molecules of NaOH = 1.204 X 10^24 molecules of NaOH
Now, calculating the individual constituents elementary atoms
Constituents 1 molecule of NaOH 1.204 X 10^24 molecules of NaOH
Na 1 1* 1.204 x 10^24 = 1.204 X 10^24 atoms of Na
O 1 1* 1.204 x 10^24 = 1.204 X 10^24 atoms of O
H 1 1* 1.204 x 10^24 = 1.204 X 10^24 atoms of H
THe MOLE mAP!~
x 1mol/MMg x Avagadro's# p./1mole x # atoms/1 molecules
Grams ------------> Moles -------------------> Ptcl-------># of atoms
x 1molecules/# of atoms x 1mol/Avagadro's# x 1 mol/MMG
# of atoms -----> Ptcl-------> Moles ------> Grams
Basically follow the map step by step, never try to be smart and skip one step!!
Well, they aren't necessarily much harder. If you master the basic stuff, this should be easy!
One thing you HAVE to keep in memory is THIS: MOLE MAP!-> you will never get lost with it!
Now, recall that MOLE is defined as the amount of substance that contains 6.022 X 10^23 atoms or molecules or subatomic particles. This numeric value 6.022 X 10^23 is also called as Avogadro's number.
So, a mole of any substance (atom or molecule) would be equal to the atomic mass/ molecular mass of that substance in gram.
Calculation1: for Element: Grams to Moles to Atoms
Lets calculate the number of atoms in 80g of calcium.Steps to be followed:
1) Find the molar mass of element
2) Conversion of mass ( 80g ) into moles.
3) Getting the multiplication of obtained moles by avogadro's number to get the number of atoms.
Since we Know that
Atomic mass of Ca= 40 g/mole
so, the number of moles in 80g of Ca = given mass / atomic mass
= 80g / 40 g/mol = 2 moles
Here we got the 2 moles of Ca from 80g of Ca.
Now, 1 mole of Ca = 6.022 x 10^23 atoms of Ca ( By definition )
Therefore, 2 moles of Ca = 2 X 6.022 X 10^23 atoms
= 1.204 X 10^24 atoms of Ca
Thus, we got that
80g of calcium contains 1.204 X 10^24 atoms of the substance Ca.
Calculation 2: for Compound: Grams to Moles to Atoms
Lets calculate the no. of atoms in a compound, say 80g NaOHSteps to be followed:
1) Find the molecular mass of substance ( here, 40g / mole)
2) Find the moles of this mass
3) convert this moles into number of molecules of substance
4) get the individual number of constituent elementary atoms
Here we know the molar mass of NaOH= 40 g/mole
So, the no. of moles in 80g of NaOH = 80g/ 40 g/mole
= 2 moles
Now, since 1 mole of NaOH = 6.022 X 10^23 molecules of NaOH
So, 2 moles of NaOH = 2* 6.022 x 10^23 molecules of NaOH = 1.204 X 10^24 molecules of NaOH
Now, calculating the individual constituents elementary atoms
Constituents 1 molecule of NaOH 1.204 X 10^24 molecules of NaOH
Na 1 1* 1.204 x 10^24 = 1.204 X 10^24 atoms of Na
O 1 1* 1.204 x 10^24 = 1.204 X 10^24 atoms of O
H 1 1* 1.204 x 10^24 = 1.204 X 10^24 atoms of H
THe MOLE mAP!~
x 1mol/MMg x Avagadro's# p./1mole x # atoms/1 molecules
Grams ------------> Moles -------------------> Ptcl-------># of atoms
x 1molecules/# of atoms x 1mol/Avagadro's# x 1 mol/MMG
# of atoms -----> Ptcl-------> Moles ------> Grams
Basically follow the map step by step, never try to be smart and skip one step!!
Monday, November 22, 2010
November 19, 2010
Mole Conversions !!!
Ahhhhh, good old mole conversions, you yet to surprise me again... ;)
Well, to mix up today's lesson I will be presenting you a powerpoint!!! Woo, Yea!!!
And this is no other normal powerpoint, noooo this is a powerpoint that will amaze your eyes and give you, yes you, important information that will be useful to what you need to know about Mole Conversions!
But first here are some videos that will also help you understand......
1) http://www.youtube.com/watch?v=_Od-lhWTG3Y&feature=fvst
2) http://www.youtube.com/watch?v=ehepBBtSbDc
3) http://www.youtube.com/watch?v=QcEyl4sG-Ac&feature=fvw
4) http://www.youtube.com/watch?v=NMdN1LtHuDA&feature=related
And here are some worksheets + questions.......
1) http://www.fordhamprep.org/gcurran/sho/sho/lessons/lesson92.htm
2) http://www.sciencegeek.net/Chemistry/taters/Unit4GramMoleVolume.htm
Powerpoint.......
(I could not save it into like a powerpoint presentation so instead down below are all of the slides in order)
Dont forget HW.......
1) Textbook pg. 104 # 4-9
2) Textbook pg. 109 # 4-16
3) Sheet - Mole Conversions Exercises; Excercise A-D
4) Sheet - Atomic Mass, Formula Mass & Molar Mass; Excercise B (Back Side)
Ahhhhh, good old mole conversions, you yet to surprise me again... ;)
Well, to mix up today's lesson I will be presenting you a powerpoint!!! Woo, Yea!!!
And this is no other normal powerpoint, noooo this is a powerpoint that will amaze your eyes and give you, yes you, important information that will be useful to what you need to know about Mole Conversions!
But first here are some videos that will also help you understand......
1) http://www.youtube.com/watch?v=_Od-lhWTG3Y&feature=fvst
2) http://www.youtube.com/watch?v=ehepBBtSbDc
3) http://www.youtube.com/watch?v=QcEyl4sG-Ac&feature=fvw
4) http://www.youtube.com/watch?v=NMdN1LtHuDA&feature=related
And here are some worksheets + questions.......
1) http://www.fordhamprep.org/gcurran/sho/sho/lessons/lesson92.htm
2) http://www.sciencegeek.net/Chemistry/taters/Unit4GramMoleVolume.htm
Powerpoint.......
(I could not save it into like a powerpoint presentation so instead down below are all of the slides in order)
Dont forget HW.......
1) Textbook pg. 104 # 4-9
2) Textbook pg. 109 # 4-16
3) Sheet - Mole Conversions Exercises; Excercise A-D
4) Sheet - Atomic Mass, Formula Mass & Molar Mass; Excercise B (Back Side)
Thursday, November 18, 2010
November 18th
A Mole Day Song! (Oh, won't you come and sing along?)
A mole is an animal that burrows in the ground,
Or a spot on your chin that you gotta shave around.
But there's another kind of mole of interest to me,
That's the kind of mole they use in chemistry.
Chorus: A mole is a unit, or have you heard,
Containing six times ten to the twenty-third,
That's a six with twenty-three zero's at the end,
Much too big a number to comprehend.
Say you had a mole of pennies to distribute 'round the world,
Give to each of the five billion grownups, boys, and girls,
There wouldn't be a single person down and out of luck,
Cause everybody in the world would get a trillion bucks.
Or say you had a mole of paper and stacked it toward the sky,
Paper's awful thin, but that pile would get so high.
It'd reach up into outer space, in fact I think you'd find,
It'd go up to the moon and back, eighty billion times.
Chorus: A mole is a unit, or have you heard,
Containing six times ten to the twenty-third,
That's a six with twenty-three zero's at the end,
Much too big a number to comprehend.
Suppose a mole of marshmallows fell upon the planet,
Over each square inch of land and sea, think that you could stand it?
That layer would be twelve miles high and of course block our sun,
We're talking close to five million trillion tons.
Well, maybe we could save ourselves if we all started eaten',
One marshmallow each second, not two 'cause that'd be cheatin',
With forty five billion people munching, how long do you think it'd take?
Forty million years, and that's without a bathroom break.
Chorus: A mole is a unit, or have you heard,
Containing six times ten to the twenty-third,
That's a six with twenty-three zero's at the end,
Much too big a number to comprehend.
But say you had a mole of atoms, would the pile be immense,
Should I say the answer now or leave you in suspense?
Well, atoms are so very small, very small, you understand,
You could hold a mole of atoms in the palm of your hand.
So shake a little sugar in the middle of your palm,
Now you don't want to spill it, so try and stay calm.
You hardly can imagine and barely realize,
There're more atoms in that sugar than stars up in the sky.
Chorus: A mole is a unit, or have you heard,
Containing six times ten to the twenty-third,
That's a six with twenty-three zero's at the end,
Much too big a number to comprehend.
Today's Class:
Atomic mass unit (amu): a way of measuring the mass of a single atom of an element. To find the amu of an element, look for its atomic mass on the periodic table.
For example, chlorine is 35.5 amu.
To find the amu of an ionic compound, add together the amu of each atom of that compound.
A mole is an animal that burrows in the ground,
Or a spot on your chin that you gotta shave around.
But there's another kind of mole of interest to me,
That's the kind of mole they use in chemistry.
Chorus: A mole is a unit, or have you heard,
Containing six times ten to the twenty-third,
That's a six with twenty-three zero's at the end,
Much too big a number to comprehend.
Say you had a mole of pennies to distribute 'round the world,
Give to each of the five billion grownups, boys, and girls,
There wouldn't be a single person down and out of luck,
Cause everybody in the world would get a trillion bucks.
Or say you had a mole of paper and stacked it toward the sky,
Paper's awful thin, but that pile would get so high.
It'd reach up into outer space, in fact I think you'd find,
It'd go up to the moon and back, eighty billion times.
Chorus: A mole is a unit, or have you heard,
Containing six times ten to the twenty-third,
That's a six with twenty-three zero's at the end,
Much too big a number to comprehend.
Suppose a mole of marshmallows fell upon the planet,
Over each square inch of land and sea, think that you could stand it?
That layer would be twelve miles high and of course block our sun,
We're talking close to five million trillion tons.
Well, maybe we could save ourselves if we all started eaten',
One marshmallow each second, not two 'cause that'd be cheatin',
With forty five billion people munching, how long do you think it'd take?
Forty million years, and that's without a bathroom break.
Chorus: A mole is a unit, or have you heard,
Containing six times ten to the twenty-third,
That's a six with twenty-three zero's at the end,
Much too big a number to comprehend.
But say you had a mole of atoms, would the pile be immense,
Should I say the answer now or leave you in suspense?
Well, atoms are so very small, very small, you understand,
You could hold a mole of atoms in the palm of your hand.
So shake a little sugar in the middle of your palm,
Now you don't want to spill it, so try and stay calm.
You hardly can imagine and barely realize,
There're more atoms in that sugar than stars up in the sky.
Chorus: A mole is a unit, or have you heard,
Containing six times ten to the twenty-third,
That's a six with twenty-three zero's at the end,
Much too big a number to comprehend.
Today's Class:
Atomic mass unit (amu): a way of measuring the mass of a single atom of an element. To find the amu of an element, look for its atomic mass on the periodic table.
For example, chlorine is 35.5 amu.
To find the amu of an ionic compound, add together the amu of each atom of that compound.
For example, Magnesium Oxide would have an amu of 40.3, because magnesium has an amu of 24.3, and oxygen has an amu of 16.0.
If the compound includes two or more atoms of a single element, add each individual atom's amu to the total amu.
Molecular Mass Formula
1 mole of an element is equal to its amu in grams per mole. For example, one mole of fluoride = 19.0g/mol.
Avogardo's Number is a formula which can calculate how many particles there are in a single mole of any amount of substance.
The formula is: 6.022 x 1023 particles/mol.
Thanks, come again soon!
Thursday, November 11, 2010
Ready for the CELEBRATION yet??
Finally, we are very close to the ending of this chapter which was all about number and value. And now, we are going to have a test on Chapter 3 on MONDAY, NOVEMBER 15th!
Materials will include:
Significant Figures, Measurement & Uncertainty, Scientific Notation, Density, Graphing, Lab 2E, and Unit Conversions! Bring a scientific calculator! Know all formulas for Volume, Area, Density, and Percent Experimental Error.
Let's have a QUICK and EASY review session with this self-quiz!
1. Sig fig include
a)certain digits b)uncertain digits c)all digits d)certain and uncertain digits
2. Which is more precise?
a)2.33 b)2.301 c)2.30 d)2.3
3. Which digit is uncertain in this value: 2.309447
a)7 b) 3 c)0 d)2
4.How many sig fig is in this value: 0.0056930
a)8 b)7 c) 5 d) 4
5. Round 0.90003 to 3 sig figs
a) 0.900 b) 0.90 c) 1.00 d) 0.900030
6. Round 0.34566 to 3 sig figa
a) 0.345 b) 0.340 c) 0.344 d) 0.346
7.Add/Subtract and express the answer in the correct sig fig: 2.40 - 10.293 + 300
a) 292.107 b) 292 c) 290 d)292.11
8.Multiply and express the answer in the correct sig fig: 3.4 x 0.0098
a)0.033 b).0.03 c).0.0 d). 0.03332
9.Calculate Absolute Uncertainty for these 3 values: 2.3, 2.4, 2.5
a) 2.4 +/- 0.1 b) 2.4 +/- 0.2
10. What is the absolute uncertainty of a ruler?
___________________________
11, What is the relative uncertainty if absolute uncertainty is 2 and estimated measurement is 39.2 ?
____________________________
12. Calculate the Mass of a object with volume of 2 and density of 5.
a) 10 b)2.5 c) 0.4
Answer Key:
1. D
2. B
3.A
4.C
5.A
6.D
7.B
8.A
9.A
10. 0.01 cm
11. 5.1%
12. A
Did you get them ALL??? Wasn't it a piece of cake?
well, that didn't cover the whole chapter. I will leave it to your own to study for calculation involved in Lab 2E (Thickness Calculation) and graphing.
GOOD lUCK STUDYING ALL!~
Materials will include:
Significant Figures, Measurement & Uncertainty, Scientific Notation, Density, Graphing, Lab 2E, and Unit Conversions! Bring a scientific calculator! Know all formulas for Volume, Area, Density, and Percent Experimental Error.
Approximately 10 Written and 40 Multiple Choice Questions for a total of about 70 marks!!
1. Sig fig include
a)certain digits b)uncertain digits c)all digits d)certain and uncertain digits
2. Which is more precise?
a)2.33 b)2.301 c)2.30 d)2.3
3. Which digit is uncertain in this value: 2.309447
a)7 b) 3 c)0 d)2
4.How many sig fig is in this value: 0.0056930
a)8 b)7 c) 5 d) 4
5. Round 0.90003 to 3 sig figs
a) 0.900 b) 0.90 c) 1.00 d) 0.900030
6. Round 0.34566 to 3 sig figa
a) 0.345 b) 0.340 c) 0.344 d) 0.346
7.Add/Subtract and express the answer in the correct sig fig: 2.40 - 10.293 + 300
a) 292.107 b) 292 c) 290 d)292.11
8.Multiply and express the answer in the correct sig fig: 3.4 x 0.0098
a)0.033 b).0.03 c).0.0 d). 0.03332
9.Calculate Absolute Uncertainty for these 3 values: 2.3, 2.4, 2.5
a) 2.4 +/- 0.1 b) 2.4 +/- 0.2
10. What is the absolute uncertainty of a ruler?
___________________________
11, What is the relative uncertainty if absolute uncertainty is 2 and estimated measurement is 39.2 ?
____________________________
12. Calculate the Mass of a object with volume of 2 and density of 5.
a) 10 b)2.5 c) 0.4
Answer Key:
1. D
2. B
3.A
4.C
5.A
6.D
7.B
8.A
9.A
10. 0.01 cm
11. 5.1%
12. A
Did you get them ALL??? Wasn't it a piece of cake?
well, that didn't cover the whole chapter. I will leave it to your own to study for calculation involved in Lab 2E (Thickness Calculation) and graphing.
GOOD lUCK STUDYING ALL!~
Friday, November 5, 2010
How was the Quiz??
Hey, everyone~
How did you do on Lab 2E Quiz today??
It was basically a complete summary of out Lab 2E: Determining Aluminum Foil Thickness.
Some of the important formulas were tested:
1. Volume = Length x Width x Height (thickness)
2. Density = Mass / Volume.
3. Mass = Density x Volume
4. Volume = Mass / Density
5. Percentage of Error = (your measurement -accepted measurement) / accepted measurement x 100%
* Also remember the answer should be positive!
I believe these will be important for the Chapter 3 test coming up too!
We also learned graphing skills on EXCEL in the computer lab...
By using EXCEL, we observed the relationship between X and Y more clearly and find the slope and equation. The slope = the Density when X is Volume and Y is Mass.
In the case of the example we did today: Temperature Vs. Density, we had to answer the question why is hot water more dense than cold water?
How did you do on Lab 2E Quiz today??
It was basically a complete summary of out Lab 2E: Determining Aluminum Foil Thickness.
Some of the important formulas were tested:
1. Volume = Length x Width x Height (thickness)
2. Density = Mass / Volume.
3. Mass = Density x Volume
4. Volume = Mass / Density
5. Percentage of Error = (your measurement -accepted measurement) / accepted measurement x 100%
* Also remember the answer should be positive!
I believe these will be important for the Chapter 3 test coming up too!
We also learned graphing skills on EXCEL in the computer lab...
By using EXCEL, we observed the relationship between X and Y more clearly and find the slope and equation. The slope = the Density when X is Volume and Y is Mass.
In the case of the example we did today: Temperature Vs. Density, we had to answer the question why is hot water more dense than cold water?
Wednesday, November 3, 2010
November 3rd
Well, hi there,,,,
this is my first time to type in this blog,, so i am kind of nervous?!
Okay,, back to the point.
For the chemistry lesson today,,
we did an experiment from the lab book, it is the 2E lab-- DETERMINING ALUMINIUM FOIL THICKNESS.
Well,,, apparantly,, it is not a hard experiement to do.
first, find three aluminium foil and measures the width and length, then weight it.
after that,, just use the formulas provided to get the answer for it
#### IMPORTANT FORMULAS####
1) Volume of a rectangular solid V=LWH (length x width x height)
2) Density of a substance D=m/V (mass/volume)
Well,, i guess that's the end for my first time?!
P.S remember that we have a quiz of the lab 2E on this FRIDAY!!! Good luck~~ =]
this is my first time to type in this blog,, so i am kind of nervous?!
Okay,, back to the point.
For the chemistry lesson today,,
we did an experiment from the lab book, it is the 2E lab-- DETERMINING ALUMINIUM FOIL THICKNESS.
Well,,, apparantly,, it is not a hard experiement to do.
first, find three aluminium foil and measures the width and length, then weight it.
after that,, just use the formulas provided to get the answer for it
#### IMPORTANT FORMULAS####
1) Volume of a rectangular solid V=LWH (length x width x height)
2) Density of a substance D=m/V (mass/volume)
Well,, i guess that's the end for my first time?!
P.S remember that we have a quiz of the lab 2E on this FRIDAY!!! Good luck~~ =]
Tuesday, November 2, 2010
November 1, 2010
Today is Monday, November 1 (can u believe that it is already November?!?!?!) and we took our quiz and started learning on our new subject: DENSITY !!!! yay !!!
Here is what we did in order:
- First we corrected our review sheet for sig figs.
- Then we took our quiz
(which was on Significent Figures, Uncertainty, Scientific Notation and Measurement)
- And for the remainder of the class we took notes on Density and we got a worksheet for homework.
* Here is a quick lesson on Density:
Facts;
- Density = mass divided by volume
- Volume = mass divided by density
- Mass = density times volume
- Density of a solid = g/cm cubed
liquid = g/mL
water = 1.0 g/mL or 1000 g/L
- If the density of an object is greater than the density of liquid the object will sink
And if the density of an object is less than the density of liquid the object will float
Examples of Density Problems (see if you can figure them out)
1) Calculate the density in g/mL of aluminum if a 50 mL block weighs135 g.
2) Calculate the mass in a 200 cc block of Titanium with a density of 4.51 g. per cc.
3) Calculate the mass of a liquid with a density of 3.2 g/mL and a volume of 25 mL.
4) An irregular object with a mass of 18 kg displaces 2.5 L of water when placed in a large overflow container. Calculate the density of the object.
5) A graduated cylinder has a mass of 80 g when empty. When 20 mL of water is added, the graduated cylinder has a mass of 100 g. If a stone is added to the graduated cylinder, the water level rises to 45 mL and the total mass is now 156 g. What is the density of the stone?
Since density is known worldwide and can be connected to so many things here are some news articles and papers that you should check out!
1. http://www.warsawvoice.pl/WVpage/pages/article.php/22750/article
2.http://news.softpedia.com/news/Saturn-s-Rings-Are-Proxies-for-Galaxies-164138.shtml
3. http://www.usnews.com/science/articles/2010/11/01/revealing-the-galaxys-dark-side.html
Here is a website that focuses all on science news and very interesting news:
1. http://insciences.org/articles.php?tag=Chemistry
Images to help with density:
A density joke that ought to make you chuckle!
- In world war 1 a great big british mine found itself sinking through the ocean right next to a great big german mine. After a while the great big british mine said - 'I say, we seem to be sinking at exactly the same rate - we must have the same density!'
'Somehow I doubt zis!' replied the great big german mine; 'It is just zat great mines sink alike...'
And four videos about Density & Volume & Mass!
- http://www.youtube.com/watch?v=fqLCwuKMBMA
- http://www.youtube.com/watch?v=rxb_6UANXqU
- http://www.youtube.com/watch?v=grWG_U4sgS8&feature=related
- http://www.youtube.com/watch?v=uvy4nWh0KwE&feature=related
Last but not least for next class....................
- We are doing Lab 2E. So dont forget to make a chart of the procedures and make a copy of Table 1.
- Finish the density problem worksheet.
Here is what we did in order:
- First we corrected our review sheet for sig figs.
- Then we took our quiz
(which was on Significent Figures, Uncertainty, Scientific Notation and Measurement)
- And for the remainder of the class we took notes on Density and we got a worksheet for homework.
* Here is a quick lesson on Density:
Facts;
- Density = mass divided by volume
- Volume = mass divided by density
- Mass = density times volume
- Density of a solid = g/cm cubed
liquid = g/mL
water = 1.0 g/mL or 1000 g/L
- If the density of an object is greater than the density of liquid the object will sink
And if the density of an object is less than the density of liquid the object will float
Examples of Density Problems (see if you can figure them out)
1) Calculate the density in g/mL of aluminum if a 50 mL block weighs135 g.
2) Calculate the mass in a 200 cc block of Titanium with a density of 4.51 g. per cc.
3) Calculate the mass of a liquid with a density of 3.2 g/mL and a volume of 25 mL.
4) An irregular object with a mass of 18 kg displaces 2.5 L of water when placed in a large overflow container. Calculate the density of the object.
5) A graduated cylinder has a mass of 80 g when empty. When 20 mL of water is added, the graduated cylinder has a mass of 100 g. If a stone is added to the graduated cylinder, the water level rises to 45 mL and the total mass is now 156 g. What is the density of the stone?
Since density is known worldwide and can be connected to so many things here are some news articles and papers that you should check out!
1. http://www.warsawvoice.pl/WVpage/pages/article.php/22750/article
2.http://news.softpedia.com/news/Saturn-s-Rings-Are-Proxies-for-Galaxies-164138.shtml
3. http://www.usnews.com/science/articles/2010/11/01/revealing-the-galaxys-dark-side.html
Here is a website that focuses all on science news and very interesting news:
1. http://insciences.org/articles.php?tag=Chemistry
Images to help with density:
A density joke that ought to make you chuckle!
- In world war 1 a great big british mine found itself sinking through the ocean right next to a great big german mine. After a while the great big british mine said - 'I say, we seem to be sinking at exactly the same rate - we must have the same density!'
'Somehow I doubt zis!' replied the great big german mine; 'It is just zat great mines sink alike...'
And four videos about Density & Volume & Mass!
- http://www.youtube.com/watch?v=fqLCwuKMBMA
- http://www.youtube.com/watch?v=rxb_6UANXqU
- http://www.youtube.com/watch?v=grWG_U4sgS8&feature=related
- http://www.youtube.com/watch?v=uvy4nWh0KwE&feature=related
Last but not least for next class....................
- We are doing Lab 2E. So dont forget to make a chart of the procedures and make a copy of Table 1.
- Finish the density problem worksheet.
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