Describe what happens to the volume of a gas when temperature is increased? When temperature is decreased?
When temperature is increased, volume of a gas increases.
When temperature is decreased, volume of a gas decreases.
(This is Charles' Law!)
200
Describe ARCHIMEDES' PRINCIPLE
Archimedes' Principle helps us predict if an object will sink/float in fluids.
It states that: an object that displaces equal/more fluid than the object itself, the object will float. An object that displaces less fluid than the object itself will sink.
300
HARDNESS is an important property of matter. Describe this property, and provide one example of something that is charachterized by HARDNESS.
HARDNESS is the property of matter that resists scratching. Mirrors, countertops, and diamonds exemplify HARDNESS.
300
Diagram the order of 5 liquids according to their density:
oil, dish soap, water, corn syrup, rubbing alcohol
Order should be placed from most dense (on the bottom) to least dense (on the top)
corn syrup, dish soap, water, oil, rubbing alcohol
300
Calculate the density of a cube with a mass of 24 grams and a volume of 3 cm3.
D = M/V
D = 24 g/3 cm3
D = 8 g/cm3
300
What happens to the volume of a gas when pressure increases? When pressure decreases?
When pressure increases, volume of a gas decreases.
When pressure decreases, volume of a gas increases.
(This is Boyle's Law!)
300
A crumpled-up piece of aluminum foil will sink in water. How could you make the piece of aluminum foil float? Be specific.
Flatten out the piece of aluminum foil. The foil must take up more surface area to displace more water.
400
Compare/contrast ELASTICITY and TENSILE STRENGTH.
ELASTICITY is the measure of a solid's ability to be stretched and return to original shape.
TENSILE STRENGTH is a measure of how much a solid can be pulled before breaking.
400
Describe what happens when a Diet Coke can and a Coca-Cola Classic can are placed in a bucket of water. Why does this happen?
The Coca-Cola Classic will sink to the bottom, the diet coke floats on the top. This happens becasue they have different density. Even though they are both the same volume (355mL), they have different mass.
400
The density of gasoline is 0.7 g/mL. What is the mass of 4 liters (L) of gasoline?
M = D x V
M = 0.7 g/mL x 4 L
M = 2.8 grams (g)
400
You purchase a helium balloon at Party City for a friend's brithday party in January. You walk outside with the balloon. Describe what happens. Which GAS LAW applies to this situation?
Becasue you walk outside in January, it is cold. With a decrease in temperature, the volume of the balloon will decrease. It will appear that the balloon is less full.
This is Charles' Law!
400
The gravitational force acting on a block is 12 N. The buoyant force acting on the block is 11 N. Will the object sink or float? Explain using a diagram!!
Gravity acts downwards, buoyancy acts upwards. Gravity is more than buoyancy in this example, and the block will sink.
500
Imagine you are a baker making a loaf of bread. Describe one property of matter that you want your bread/dough to have, and one property of matter that you DO NOT want your bread/dough to have.
Answers vary:
Dough should be malleable or elastic. Baked bread should have little density. Bakes bread should not be brittle or very dense, etc.
500
Describe (in detail!!) how to calculate the density of a LIQUID.
Measure mass of empty G.C. Pour in certain volume of liquid (and record). Measure mass of G.C. with liquid, and subtract mass of empty G.C. Calculate volume by mass/volume. (Units in g/mL)
500
Ice floats in water, and pure water has a density of 1.00 g/mL.
a.) predict what the density of ice should be
b.) explain why ice floats in water
The density of ice is LESS THAN water (it is 0.92 g/mL)
Ice floats in water becasue it is less dense than water. When water molecules freeze, there is some air trapped between the molecules when they are "frozen" in place.
Water is unique in this way! Most substances are more dense when they are in a solid form. If frozen water (ice) was more dense than liquid water, lakes and rivers would freeze from the bottom up. This would negatively affect plants, animals, and ice skaters!!
500
The equation we use to describe Boyle's Law is:
P1 V1 = P2 V2
(P = pressure, and V = volume).
Solve the following problem.
A balloon has a begining volume of 5 L, and a pressure reading of 20 mmHg. Then the pressure is increased to 50 mmHg. What is the ending volume of the balloon?
Hint: Make a list of "givens" first!
P1V1 = P2V2
P1 = 20 mmHg
V1 = 5 L
P2 = 50 mmHg
Re-arrange to solve for V2
V2 = P1V1/P2
V2= (20 mmHg)(5L)/(50 mmHg)
V2 = 2 L (becasue the pressure increased, the volume decreased!)
500
Describe an object that has NEUTRAL BUOYANCY. Include a diagram or examples.
An object with NEUTRAL BUOYANCY just floats in water, but is half-way between surface and bottom. The gravitational force and buoyant force are EQUAL. Fish and submarines often use neutral buoyancy to "hover" in water.