Density Column Physical and Chemical Properties and Changes

 Bell Work 09/11/2012  First, write LEQ above.  Write Questions and Answer  What are the appropriate units for mass, volume, and density?  How do you calculate density?  Mass = kg, g  Volume = cm ³, m³  Density = g/cm³, g/L, g/mL, kg/L, kg/m³  D = M/V

 Use water displacement to obtain Volume -or- calculate mathematically  Remember that 1 cm ³ = 1 mL  To calculate volume of cylinder:  Use triple balance beam/electronic balance to measure the mass of object

 Bell Work  Write Question and Answer  What do you think a density column is?

 Write the following information and calculate the density:  Water  volume: 1.5 mL mass: 1.5g  Vegetable oil  volume: 1.5 mL mass: 1.38 g  Dish soap  volume: 1.5 mL mass: 1.59 g  Rubbing alcohol  volume: 1.5 mL mass: 1.22 g  Lamp oil  volume: 1.5 mL mass: 1.20 g

 Bell Work  Write Question and Answer  Observe the magnesium strip.  What are some physical properties of magnesium? What are some chemical properties?  Propose a way you could physically change the magnesium strip and one way you could chemically change the magnesium strip.

 What is a property?  A unique characteristic that categorizes (groups or identifies) objects/substances together

PHYSICAL PROPERTIES  Characteristic observed or measured without changing substance  Melting point, boiling point, color, size, ductility, malleable, density, ability to conduct heat or electricity CHEMICAL PROPERTIES  Ability to change from one substance to a new substance  Ability to produce a gas, burn, rust  Example: Copper w/ moist air

PHYSICAL CHANGES  does not change the identity or chemical makeup of the substance  Cutting, melting, drawing into wire, crushing, temperature and pressure changes CHEMICAL CHANGES  Substance changes into new substance b/c chemical bonds have been broken or made  Occurs on molecular level  Noticed by temperature change, smell/odor, bubbles (gas), rust formation  Reactants  products

 PREDICT:  Write down a prediction of what you think will occur upon mixing lead nitrate and potassium iodide.

 Extra Credit: (3 points to test grade)  Search the internet for important uses of Potassium Iodide. Write down any important uses and turn in tomorrow.  Also, while you are searching the internet, see if you can find why Potassium Iodide should be stored in a closed amber colored bottle.

 Propose a way you could physically change each of the following. Write down your answer.  Propose a way you could chemically change each of the following. Write down your answer.  Discuss with your group.

SubstancePhysical changeChemical Change Alka-seltzer tablet Banana Paper

 Law of Conservation of Mass  Mass cannot be created or destroyed in ordinary chemical and physical changes  Therefore, the mass before the reaction will be equal to the mass after the reaction

 Homework Assignment:  Pg. 465 #’s 1-5  Pg #’s 4, 8, 10,  Pg. 472 #’s 4, 6, 7