Quiz Study Guide

Science P.7

Safety

  • Test liquids by wafting them.
  • If something spills/breaks, get Mr. Leeds.
  • Wash hands with soap and water after working with chemicals.
  • Never use force when working with glass.
  • Make sure lab area is clean before leaving class.
  • Caping the alcohol burner puts out the flame because fire needs oxygen.
  • Wear safety goggles until Mr. Leeds says to take them off.
  • The nurses number is 2828.
  • Report all accidents to Mr Leeds as soon as it happens.
  • Never throw broken glass into the regular trash bin.
  • If chemicals get on your skin, you should flush with water and tell Mr. Leeds.
  • Be careful because hot and cold glass look the same.
  • Don't use cracked test tubes.
  • Keep safety goggles on even when cleaning up.
  • clean up after every experiment.
  • The emergency blanket is used when a person is on fire to wrap around them.


Three important safety tips when working with an alcohol burner:


  1. Never leave a burner
  2. Cap flame when done
  3. Be careful picking up burner


Three safety precautions you should take when using chemicals:


  1. Don't touch chemicals
  2. Don't taste chemicals
  3. Only waft chemicals


Three pieces of safety equipment located within classroom:


  1. Fire extinguisher (near front door)
  2. safety blanket (in the back)
  3. eye wash (opposite of front door)

Reaction in a Bag Lab

  • Purpose: to record the observations that occur when multiple chemical substances are combined and to use my observations to understand the reactions of the chemicals.


Substances:


Red liquid (phenol red)

  • ph indicator

Calcium chloride (Substance A)
  • calcium and chloride
  • mildly acidic
  • hydrotropic
  • absorbs water
  • used in:
  1. canning vegetables (keeps them from getting mushy)
  2. sports drinks
  3. flavored pickles (salty flavors)

Sodium bicarbonate (Substance B)
  • not acidic
  • baking soda
  • used in:
  1. baking,
  2. toothpaste
  3. laundry detergent

Baking Soda Lab

  • Purpose: to observe and record the reaction that occurs when baking soda is heated.


Post Lab
  • Condensation/moisture from top of test tube comes from hot gas touching cooler top of tube; turns back into liquid (gas is from baking soda)
  • Heated VS Not Heated: color difference
  • control group: unheated test tube
  • experimental group: heated test tube
  • indicator: tea (shows that heated test tube is not baking soda)
  • variable: something you try to measure
  • independent variable: causes a change in dependent variable (temperature [heat])
  • dependent variable: color of the tea

Control Factors
  1. same type of tea
  2. same amount of tea
  3. same amount of baking soda
  4. same temperature
  5. same stirring time
  6. same size tube

Volume Notes

Volume:
  • Unit of measurement: cm3 (cubic centimeters)
  • volume: LxWxH
  • Standard unit of length: meter
  • One centimeter= .01m


Volume of Liquids:

  • use graduated cylinder to measure volume
  • units: milliliters (mL)


Balance Notes

  • check that pan is clean and dry
  • zero balance before massing
  • push all riders to zero
  • adjust if needed
  • never switch pans
  • pick up balance by red bar only
  • don't zero balance when done