Daily TAKS Connection: Density, Viscosity, and Buoyancy

1
Daily TAKS ConnectionDensity, Viscosity, and
Buoyancy

• The student knows relationships exist between
  properties of matter and its components. The
  student is expected to
• (A) Investigate and identify properties of fluids
  including density, viscosity, and buoyancy.

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Extensive and Intensive

• Extensive properties depends on how much of the
  substance is present. Ex. mass, length, volume
• Intensive properties does not matter how much
  you have, the property is the same. Ex.
  density, specific heat, freezing point, boiling
  point

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Density

• Physical property
• Intensive
• How much mass, stuff, is packed into the same
  volume.

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Density

• Same stuff, less volume more dense

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Density

• Ratio that compares the mass of an object to its
  volume.

P M g ____
____ V
cm3
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Density

• Different materials have different densities

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Density

• The more dissolved solids in a liquid the greater
  the density of the liquid.

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Question 1

• Swimmers find that they can float more easily in
  the ocean than in a freshwater lake. The most
  likely reason for this phenomenon is that the
• a. viscosity of lake water is greater than that
  of ocean water
• b. density of ocean water is higher than that of
  lake water
• c. temperature of lake water is lower than that
  of ocean water
• d. mass of ocean water is greater than that of
  lake water

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Question 2

• A sample of water from a river has a greater
  density than a sample of distilled water. Which
  is the best explanation for the difference in
  density?
• a. Rivers have kinetic energy.
• b. Rivers contain dissolved minerals.
• c. Distilled water has a neutral pH.
• d. Distilled water can contain dissolved gases.

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Question 3

• Today, the observation that an air bubble in
  water rises to the surface is explained by the
  principle of
• a. viscosity
• b. interference
• c. buoyancy
• d. polarity

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Question 4

• A bar of soap is produced that sinks to the
  bottom of a container of water. Which of these
  processes could cause the bar of soap to float in
  water?
• a. Making grooves in the surface of the thick
  paste
• b. Letting the thick paste sit for four days
• c. Adding air bubbles to the thick paste
• d. Chilling the mold filled with the thick paste

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Density

• density is constant, regardless of how much
  material is present (example a drop of pool
  water has the same density as a gallon of pool
  water and has the same density as pool full of
  water)
• The density of water is 1 g/ml (materials w/ a
  density lt1 float materials w/ a density gt1 sink)

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Day 3 notes continued.

• density of solids gt density of liquids gt density
  of gases

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Question 5

• A block of maple wood with a volume of 405 cubic
  centimeters and a density of 0.67 g/cm3 is sawed
  in half. The density of the two smaller blocks is
  now
• a. one-fourth the original density
• b. two times the original density
• c. one-half the original density
• d. the same as the original density

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Question 7

• The table shows properties of four liquids that
  are insoluble in water. If the four liquids are
  poured into an Erlenmeyer flask containing water,
  which liquid will form a layer below the water?
• a. Q
• b. R
• c. S
• d. T

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Question 6

• Compared to 150 g of gaseous carbon dioxide, 150
  g of liquid carbon dioxide has greater
• a. volume
• b. mass
• c. temperature
• d. density

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Day 4 notes

• Turn to page 3 of foldable, Even More Density
• Record formula for density from the formula chart
  in your notes on page 3.
• Copy the information from the following chart
  into your foldable.

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Question 8

• What is the density at 20C of 12.0 milliliters
  of a liquid that has a mass of 4.05 grams?
• a. 0.338 g/mL
• b. 16.1 g/mL
• c. 2.96 g/mL
• d. 48.6 g/mL

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Question 9

• Which of the following objects will float on
  water?

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Density notes

• Copy formula onto the calculation triangle
• use calculation triangle to write formula needed
  to solve for mass
• use calculation triangle to write formula needed
  to solve for volume

Calculation Triangle
m
D
v
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Question 10

• What is the mass of a 250.00 mL sample of
  seawater with a density of 1.025 g/mL?
• a. 243.9 g
• b. 256.25 g
• c. 250.0 g
• d. 312.5 g

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Question 11

• A sample of an element has a mass of 75.0 g and a
  density of 1.25 g/mL. What is the volume in
  milliliters of the sample? Record your answer to
  the nearest tenth.

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Question 12

• A 250 mL quantity of vanilla ice cream has a mass
  of 200 grams. The manufacturer then bubbles air
  into the ice cream so that its volume increases
  by 150 mL. What is the ice creams approximate
  final density?
• a. 0.30 g/cm 3
• b. 0.80 g/cm 3
• c. 0.50 g/cm 3
• d. 1.30 g/cm 3

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Viscosity Notes

• Fluids with low viscosity flow quickly
• Fluids with high viscosity flow slowly
• heating a fluid decreases viscosity cooling a
  fluid increases viscosity
• Ex Warm honey flows more quickly than cold honey.

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Question 13

• Students in a chemistry lab measure the time it
  takes four different 50 mL solutions to pass
  through a hole in the bottom of a cup. Which of
  the following properties of the solutions is most
  likely being measured?
• a. Buoyancy
• b. Viscosity
• c. Mass
• d. Volume

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Question 14

• As the viscosity of a liquid decreases, the
  liquid
• a. conducts electricity
• b. evaporates more quickly
• c. pours more quickly
• d. forms a precipitate

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Question 15

• Brown sugar consists of crystals of white sugar
  coated with molasses. If brown sugar hardens, it
  can be softened by heating. The most likely
  reason brown sugar softens when heated is that
  heat
• a. increases the moisture of sugar
• b. increases the density of sugar
• c. decreases the volume of molasses
• d. decreases the viscosity of molasses