Chemistry: data analysis volume, density, temperature, scientific notation 8/27/15

Music to remember https://www.youtube.com/watch?v=IhtgKHYZti0 https://www.youtube.com/watch?v=Jr5yy_hb1QA

volume Is the space occupied by an object. Derived Unit: m3 Most useful is cm3 Works well for solid objects w/ regular dimensions But not so well for liquids or solids w/ irregular shapes 1 cm3 = 1 mL volume

Density Is a ratio that compares the mass of an object to its volume. Density (ρ) = mass (m)/volume (v) Units: g/cm3=mass (g)/volume (cm3) 1 cm3 = 1 mL It’s easier to lift a grocery bag full of paper goods than it is to lift a grocery bag full of soup cans. Volume of the bags are identical…so it must have something to do with the amount of mass packed into the same volume!

The quarter and the foam weigh the same…but the density of the quarter is much greater than the density of the foam because the quarter occupies a much smaller space.

I calculate Density (ρ) = mass (m)/volume (v) Units: g/cm3=mass (g)/volume (cm3) Mass = 13.5 g Volume = 5.0 cm3 What is the density of the aluminum? 13.5g/5.0 cm3 = 2.7 g/cm3 Every sample of pure aluminum has the same density (that goes for any pure sample of anything).

densities http://periodictable.com/Properties/A/Density.al.html

I calculate Suppose a sample of aluminum is placed in a 25 mL graduated cylinder containing 10.5 mL of water. The level of water rises to 13.5 mL. What is the mass of the aluminum, if its density is 2.7 cm3 ?

We calculate What is the volume of a sample that has a mass of 20 g and a density of 4 g/mL?

We calculate A metal cube has a mass of 20 g and a volume of 5g/cm3. Is the cube made of pure aluminum? Explain your answer.

You Calculate What is the density of a piece of wood that has a mass of 25.0 grams and a volume of 29.4 cm3 ?

You Calculate A piece of wood that measures 3.0 cm by 6.0 cm by 4.0 cm has a mass of 80.0 grams. What is the density of the wood? Would the piece of wood float in water? (HINT: volume=LxWxH)

Practice I threw a plastic ball in the pool for my dog to fetch. The mass of the ball was 125 grams. What must the volume be to have a density of 0.500 g/mL? (I want it to float of course!)

Temperature conversions The temperature of an object is a measure of how hot or cold the object is relative to other objects. Hot and cold are qualitative descriptions. To get quantitative data, you need tools to measure with. In a thermometer, liquid expands when it’s heated and contracts when cooled. The tube contains liquid in a narrow enough area that small changes in temperature can be detected.

Celsius Devised by Anders Celsius, a Swedish astronomer. He used temps where water freezes and boils for his scale b/c they were easy to reproduce. Freezing pt = 0 Boiling pt = 100 Divided distance between these pts into 100 equal units, or degrees Celsius Celsius

Kelvin (K) Scottish physicist and mathematician, William Thomson (Lord Kelvin) SI base unit for temperature Water freezes at 273 K and boils at 373 K

Converting between the two scales To convert temperature reported in Celsius to Kelvins, just add 273. -39 °C + 273 = 234 K 357 ° C + 273 = 630 K To convert from the Kelvin scale to Celsius, just subtract 273. 266 K – 273 = -7 °C 332 K – 273 = 59 °C

I calculate Convert 26 °C into Kelvins Convert 650 K into °C

We calculate Convert 15 °C into Kelvins Convert 150 K into °C

You Calculate Convert 5 °C into Kelvins Convert 245 K into °C