Class Blog 8/30/13

Questions of the Day

• How did you do on yesterday's quiz? What can you learn and remember from what you go wrong?
• What are the signs of a chemical change? In other words, how do we know when bonds break and new bonds form?
• What is so special about the metric system?
• What is the difference between precision and accuracy?
• How does that relate to the lab equipment?

Notes

- Signs of Chemical Change

1. gas formation/ solid formation(precipitate)
2. new smell
3. change in state
4. different/new property
5. ability to react with something change
6. spontaneous change in temperature
7. fizzing/bubbling
8. new color
9. emission of light(glowing)
10. new texture

This all indicates the FORMATION OF SOMETHING NEW

Any of these signs can happen but they may not always be signifying a chemical change! It could just be a physical change! (i.e. food coloring. temperature change.)

-Precision vs. Accuracy

Accuracy: when you get close to the real answer

Precision: when all your measurements are constantly close to each other 

** you CAN be precise without being accurate

** you CAN'T be truly accurate without being precise

-Metric Units & Conversions

• length: meter
• mass: gram                    Base Units
• volume: liter (meter^3= 1000 liters)

Kilo

          x10

Hecto

          x10

Deca

          x10

Unit(meter, gram, liter)

          x10

deci

          x10

centi 

          x10

milli

  **shift decimal to convert from one unit to the other

Reminders!

- Don't be afraid to go to the TCL for help!

        They're more than happy to answer questions

                                                   help study for tests and quizzes

                                                   webassigns

- Tips: use your textbook! It's a good idea to look over material before Ms. Friedmann talks about it.

- Don't be afraid to email Ms. Friedmann with questions or concerns! But remember that Ms. Friedmann has her own life too!

- For those of you who haven't taken the quiz yet, make sure to take care of that!

NEXT SCRIBE: Elaine Sine

Class Blog 8/29/13

Class Blog 8/29/13

Questions of the Day:

How comfortable do you feel with telling the difference between…

• Elements and Compounds
• Mixtures and Pure Substances
• Atoms and molecules

What is the difference between a property and a change?

How is physical different from chemical?

Things We Did in Class

• Checked in Homework-- Particulate Nature of Matter (Went with the Chemthink tutorial and quiz) CHemthink: http://chemthink.com/chemthink.htm, and the notes we took on our tutorial
• Went over the paperclip activity done in class yesterday
• Went over the Particulate Nature of Matter homework
• Took notes on Properties v. Changes (see notes)
• Took Quiz on Chemical v. Physical Changes
• See Ms. Friedman for a make-up (likely in test center)
• Wrote downs signs of a chemical change with a buddy (see notes)

Notes:

Properties v. Changes

Property= Substance’s potential to changes Ex. ability to react with an acid, melt at 50 degrees celsius

Change= Before and after. The actual process of reacting with an acid, or melting

Physical Changes:

• Identity of substance stays the same

Chemical Changes:

• Identity of substance changes

Signs of a chemical change:

color

texture

heat

smell

reaction

flammability

melting point

freezing point

state of matter

Homework:

1) WebAssign 1.2 -- Measurement and Sig Figs.  Due Saturday night by 11:59 pm.  A friendly suggestion:  plan your weekend accordingly!  Since you have no other homework for now, I strongly suggest you work on this assignment tonight.  You do not need to finish WebAssigns all in one sitting; you can save your work and come back to it later.  If you choose to do this, however, do not forget about your Saturday night deadline as you enjoy Friday and Saturday!

Reminders:

• Make sure to check the Moodle every night for homework
• Get googles in the bookstore ASAP

Next Blogger: Francine Yoon

Wednesday, 8-28-13 BLOG

* Checked in homework

* Picked up 4 sheets at the beginning of class (Check moodle handouts folder)

* Registration for ChemThink (Make sure username is First and Last name) If you were not here, look at "ChemThink Registration Directions" in the Unit 1 Handouts folder and follow the directions to register.

* Paperclip Activity

Paperclip Molecules

A couple notes:
- Plus signs (+) is a mixture
- No plus sign is a chemical bond
- More than one atom stuck together is a molecule


Ask yourself
     - Element or compound?
     - Mixture or pure substance?
     - Atoms or molecules?

* Homework: 

1) Read sections 1.1 and 1.2 in your textbook.  WebAssigns 1.1 and 1.2 are due tonight by 11:59 pm.

2) Log onto ChemThink and complete the Particulate Nature of Matter tutorial AND quiz.  As you complete the tutorial, take notes in your journal.  Due tonight by 11:59 pm.

3) Particulate Nature of Matter worksheet (in the Unit 1 Handouts folder).  Due tomorrow.


4) In-Class quiz tomorrow on what we've learned so far. Review blogs and do homework:)

Next Scribe: Melissa Scherer

Class Notes 8/27/13

---

• Grab handouts on variables and experimental design and on substances from the table.

Questions of the Day

• What did you think of the observation lab? What did you learn from it?
• What were the three kinds of variables we talked about yesterday?
• How do chemists classify matter?

Reactions to the Observation Lab

• “It was very interesting”

• “It was a lot of fun”
• Purpose was to learn about how experiments are to be done in this class and  to learn about the experimental process

Review of Variables

“Independent Variable

• What I change (As experimenter)

Dependent Variable

• Data
• What I observe and measure
• Qualitative Observations
• No numbers
• Quantitative Observations
• Has numbers and measurements

Controlled Variable

• Everything you try to keep the same from trial to trial”

- Danny Shiller

Classifying Matter

Pure Substances

Elements

• 110 of these.
• Can’t be broken down.
• All atoms of an element are identical.

Compounds

• Different elements that are combined chemically

Mixtures

Homogeneous

• Same throughout

Heterogeneous

• Different throughout

The next scribe is Allie Boland

MONDAY 8/26/13

Questions to be answered in class:

• What are the 3 main kinds of experimental variables?
• What is the difference between qualitative and quantitative observations?
• How do you write a lab?

Note: When writing in carbon paper journal, put plastic card in between pages so the writing does not bleed through.

When Using the Textbook to Read

• Reading Matters
• Read the textbook 
• Look at diagrams
• Think about the reading
• Use the book to complete handouts
• Handouts given in class:
• Ch. 1.1 - Types of matter
• Ch. 1.2 - Measurements

Note: The purpose of today's lab is to familiarize you with being in the lab. Also to get you used to isolating variables

What are the 3 main types of variables? and What are Quantitative and Qualitative Observations?

• Independent Variable
• What I change (As experimenter)
• Dependent Variable
• Data
• What I observe and measure
• Qualitative Observations
• No numbers
• Quantitative Observations
• Has numbers and measurements
• Controlled Variable
• Everything you try to keep the same from trial to trial

How to Write a Lab

• When performing a lab, keep it neat enough for yourself to read because you will not be turning it in.
• You will turn in the lab notebook with carbon pages so do make that one neat.

Review: You can be messy on your copy of the lab, but must be neat on the copy you are turning in.

Lab Notebook Appearance 

• Title
• Name
• Lab partner's name
• Purpose of the lab
• Section on data
• Calculations (Which are not on today's lab)
• Post Lab Questions - Complete sentences, and do not rewrite questions, keep them numbered
• Conclusion (Not in today's lab) 

Today's Lab 

Observation Lab

Pre-Lab

• Don't be biased 
• Being biased is not a characteristic of the scientific method

After the procedure fill out the data with your results

Original substances and observations:

• Calcium Chloride
• White, powdery, little balls, smells like chlorine
• Sodium Bicarbonate
• White, powdery, no smell
• Phenol Red
• Red, transparent, smells like rubbing alcohol
• 5 ml. of water
• Clear, odorless

Result of all four substances combined:

• Yellow, warm then cold, bubbly 

Rest of lab is combinations between W (water), Calcium Chloride (C), Sodium Bicarbonate (S), and Phenol Red (R)

• C+S= Hot to cold
• C+R= Gets red and warm
• C+W= Gets warm and watery
• S+W= Gets Milky

The rest of the lab was the post lab questions. I am not sure if I am to write those also. The lab can be found on moodle on our class page under handouts. 

Thank you; that is all for me. 

The next scribe will be Conrad Mordsinski

Class Journal 8/23/13

REMINDERS:

-check moodle/blog every night

-read lab online for monday; understand

-first webassign quiz on safety

-class dojo codes: you can change your monster online:

(used for checking in hw; adding points for labs)

WHEN BLOGGING:

-post by 11 or 12 o'clock before the next day

-if you get sick or can’t do it you can find someone else; help each other out!

-pick someone who hasn’t gone yet

 

SAFETY VID #2:

Dressing for safety

-do not wear loose clothing

-wear fabrics that are sturdy and natural

i.e. polyester can melt and burn

-closefitting clothes but not too tight that might restrict movement

-preferably old clothes with lab apron

-sturdy close-toed shoes

i.e. leather

*try not to wear flip flops; be conscience

-tie up loose, long hair

-remove rings, watches, etc.

-glasses>contacts

*contacts are allowed

-always wear goggles with side shields even with glasses

-ALWAYS protect hands

Behavior in Lab

-NO fooling around

-keep aisles clear

-stand on step stool to reach

-eyes should be at the same level as the measurement you're reading

-keep makeup outside lab

-NO eating or drinking in lab

-do NOT squirt squeezy bottles unless specifically instructed by teacher to do so

Emergency equipment

-if cut:

1. wash wound

2. remove glass

3. dry skin carefully

4. go to nurse for bandage

-if chemical gets in eyes:

1. rinse eyes in eye wash fountain

2. take out contacts; continue washing for at least 15 min

3. go to doctor

-if spill on skin:

A. 1. rinse in lab sink

B. (if chemicals on clothes)

1. safety shower immediately thoroughly

2. take off all clothes

3. continue at least 15 min in shower

FIRES

-small fires:

1. put out by covering

2. turn off burner

-large fires:

1. teacher uses fire extinguisher

2. if fire is too big, leave room call fire department

-clothing fires:

A. 1. stop drop and roll

    2. to keep flames away from face wrap fire blanket around body

B. 1. safety shower

DEMONSTRATION:

-hexane vapor lights on fire very easily even though you can't see it

NEXT SCRIBE:

Danny Schiller