Two Step Conversions!

Last class, we learned about the basic unit conversions. You might think it's simple, however, it is the fundamental basics which you would need in order to do future conversion problems. Today, we learned about not one step, but two step conversions!

What is it, you may ask?

Well, for more complicated conversions, you would have to convert more than once to get to your designated unit. Convert it to the 10^0 prefix which are grams, meters, seconds, and Litres. To do this, you would have to have a "travel route":

Eg. Converting 50km into cm:
km -> m -> cm

You would have to convert kilometers to meters first, then convert that to centimeters.

50km x 1000m/1km x 100cm/m = 5000000cm

NOTE: Always have the unit you want to cancel on opposite sides of the fraction!! Also, leave the answer in scientific notation if the answer is either too large or too small. (eg. 5000000cm = 5.0 x 10^6cm)

Eg. Convert mg to dg:
We would have to first convert mg to grams, then from grams to decigrams.


Derived Quantity Conversions

• it is when there is more than one SI base unit in a single quantity 

         Eg. 10km/h or 10m²  

• convert to the unit on the numerator first then convert the denominator
  
  Eg. 10km/h to cm/s:
  
  10km/h x 1000m/km x 100cm/m x 1h/3600s
  Then you can cancel all the units you have repeated until you are left with cm/s

• if the unit is squared or cubed, you will have to multiply the conversion factor as many times as it is powered
  
  Eg. 10cm³ to m³
  10cm³ x 1m/100cm x 1m/100cm x 1m/100cm

Then you can cancel out all the "cm" units since it corresponds to the power, and the product of the "m" unit would be cubed.

That is all there is to converting with more than one step!! Make sure to memorize your SI prefixes and conversion factor chart to help you with your conversions!

P.S: We will have a quiz next week about conversions and scientific notations, so be sure to memorize your chart! 

I hope that all this math isn't hurting your head! :P Goodluck!

(Today's entry by Grace Zhao)

Unit Conversions!

 

-Unit conversions is all about the converting from a form of unit to another, for example, convert 100 Centimetre to metres, or it could be convert 1 centimetres to kilometres.

-measurements can be answered in different forms for different purposes but in the end, it is the same measurement

Quantities

- Many of the measurements that we do, normally it has 2 things: the number and the unit, when we combine it together it is called quantities

SI Units

-we use this system to help us convert units into different forms, SI stands for systeme Internationale and it was derived from France

-it was using powers of ten to determine the unit
Measurement                                          Unit                                                   Abbrev.
length                                                   metre                                                         m
time                                                     second                                                       s

mass                                                    gram                                                          g

amount of substance                             mole                                                          mol.
luminous intensity                                 candela                                                      col
temperature                                         Kelvin                                                        K
electric current                                     Ampere                                                     A


Conversions
-Refer to SI Prefixes and Conversion factors to guide us to find the answer

-One note to help you, it is to always remember a given value with a variable x, and when you multiple the conversion factor, the variable x must be the denominator so then you can cross the "like" factors

For ex./ Convert 8 cm to m
8 cm X 1m/ 100cm, so then the cm is crossed out because it is the same variable.
the answer is 0.08 m or 5 X 10 to the power of -2.

For more info, go to this youtube video, it might help you better to understand the Unit Conversions and hot to do them:

http://www.youtube.com/watch?v=ppaCtBbwISo&feature=relatedent

P.S. You will have to memorize this chart!

BUT.... You only have to remember all of the except...yotta, zetta, exa, peta, yocto, zepto, atto, ferto. So that's not a lot to memorize!



YAY!!!!

This entry is by Stephanie Tsui!

WHMIS/Safety

                                                                                                                                                                                Sept. 12^th 2011

Today we learned a lot of what not to do in the chemistry lab, at SpongeBob’s expense. We also renewed WHMIS, which stands for what?

Hopefully you didn't just make up something random on the spot.

Workplace Hazardous Material Information System.

Generally, hazardous materials can be split up into 6 classes:

Class A: Compressed Gases

-heat or impact can cause an explosion

Class B: Flammable/Combustible Materials

-fire hazard

-can burst into flames in contact with air/water

Class C: Oxidizing Materials

-can burn skin/eyes

-can cause flammable/combustible materials to take action

Class D: Toxic/Biohazardous Materials

-potentially fatal, even in small doses

-could be fatal/cause permanent damage after repeated exposure

-can include organisms and viruses

Class E: Corrosive Material

-materials able to corrode skin or metals

-includes gases with corrosive properties

Class F: Dangerously Reactive Materials

-materials which can react dangerously when in contact with heat or pressure

The level of danger that the substance poses can be identified by the shape surrounding the WHMIS symbol.  The symbols below are known as International Safety Symbols.

Danger! The octagon represents the highest level of danger.

Warning! The diamond symbolizes a moderate danger.

Caution! The upside-down triangle represents the lowest level of danger.  That being said, it is still hazardous!

We reviewed the equipment and their uses.  And some of us learned that what we used in class wasn’t actually called a ‘thingy.’

We were also enlightened on what is expected of us on lab days.  Most of it is common sense, but some of us need reminders on the basics.

-no running

-hair should be up

-clean up spills immediately

-no eating

-wear safety goggles at all times

-closed toed shoes

-no smelling/drinking unknown (or even known...) substances

A reminder that we have a quiz on safety this Friday.  Last year I didn’t know where the fire extinguisher in our classroom was.  A hint to anyone in that situation this year – there’s a big label right above it.  As long as you have glasses/eyes, you should be fine.

In case it isn’t already glaringly obvious, I have never blogged before.  I actually have no idea what I’m doing.  Be nice to me. I need a blogging for smartypants book.

XOXO BerylliumChemists

(Today’s entry by Heather LePard J )