Chap 1 Matter, Measurement, Calculations

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Chap 1Matter, Measurement, Calculations

• What is Chemistry what is it good for?
• What is matter ?
• Properties changes
• Classifying matter
• Measurement, units, significant figures
• Units in calculations
• Calculating percentages
• Density

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Physics, engineering, materials, etc
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What does this represent?
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How would you classify these?
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Classification
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What is going on here?Discuss with a neighbor
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Measurement
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Measurement
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Temperature scales
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• CONVERSIONS FROM ONE TEMPERATURE SCALE TO ANOTHER
  
• Readings on one temperature scale can be
  converted to the readings on the other scales by
  using mathematical equations.
• Converting Fahrenheit to Celsius.
• C 5/9(F-32)
• Converting Celsius to Fahrenheit.
• F 9/5(C 32)
• Converting Kelvin to Celsius.
• C K-273
• Converting Celsius to Kelvin
• K C 273

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Unit Conversion

• Conversion factor
• a ratio, including units, used as a multiplier
  to change from one system or unit to another
• 1 lb 453.6 g
• Example convert 381 grams to pounds
• Example convert 1.844 gallons to milliliters

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Lets practice scientific notation, significant
figures unit conversions(see handouts and
examples on board)
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Activity

• Perform the following conversions.
• 0.290 g to mg
• 1.5 km to mm
• 2 qt to ml
• 1500. cm to yards
• -20.2 degrees F to K

Possibly useful 454 g 1.00 lb 946 ml 1.00
qt 2.54 cm 1.00 in
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Volume

• Space occupied by solid, liquid or gas
• V (units of length)3
• Base unit Liter (L)
• 1 mL 1 cm3 1 cc

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• DENSITY
• Density is the ratio of the mass of a sample of
  matter divided by the volume of the same sample.
• EXAMPLE OF A DENSITY CALCULATION
• A 20.00 mL sample of liquid is put into an empty
  beaker that had a mass of 31.447 g. The beaker
  and contained liquid were weighed and had a mass
  of 55.891 g. Calculate the density of the liquid
  in g/mL.

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• PERCENTAGE
• The word percentage means per one hundred. It is
  the number of items in a group of 100 such items.
• PERCENTAGE CALCULATIONS
• Percentages are calculated using the equation
• In this equation, part represents the number of
  specific items included in the total number of
  items.

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• EXAMPLE OF A PERCENTAGE CALCULATION
• A student counts the money she has left until pay
  day and finds she has 36.48. Before payday,
  she has to pay an outstanding bill of 15.67.
  What percentage of her money must be used to pay
  the bill?
• Solution Her total amount of money is 36.48,
  and the part is what she has to pay or 15.67.
  The percentage of her total is calculated as
  follows