Matter
What are the two categories of pure substances?
Elements and compounds.
What is the name of a mixture where all particles are mixted uniformly, you cannot see the different parts?
Homogenous mixture, or a solution
Calculate the concentration of 100g of salt in 50mL of water.
2g/mL
In order to be buoyant in a fluid, what must be true about density?
The object must be less dense than the fluid surrounding it.
Where would you feel greater air pressure?
-In Lethbridge
-On top of Mount Everest
-Lethbridge (more air above us)
What category would water fall under?
-Compound
-Element
-Mixture
Compound (H2O)
Butter is an example of what type of mixture (hint - there are fat molecules in both milk and butter that do not settle)
Colloid
Which is more concentrated?
A - 6g salt in 50mL water
B - 4g salt in 25mL water
B - 0.16g/mL concentration
Why is a fluid like syrup considered to be viscous? What are the particles doing?
There is high friction between the particles.
Yes - a fluid is anything that does not have a fixed shape and flows.
Is Solid, liquid, or gas most easily compressed? Why?
Gas - it has the largest space between the particles
List the solute and solvent in a sugar/water solution.
Solute - sugar
Solvent - water
If a fluid has a density of 0.5g/ml, and you collected 40g of it, what would be the volume collected?
v = m/d v = 40/0.5
V = 80mL
Because of the high concentration of salt in the dead sea, the water is very dense due to so many salt particles being present. In comparison, humans are much less dense, causing us to float easily in the water.
What is the difference between hydraulic and pneumatic systems?
Hydraulic uses a liquid under pressure, pneumatic uses compressed air.
Describe what is happening to the particles in an ice cube as it melts.
They are speeding up and moving further apart as heat is added, causing a state change from solid to liquid.
If we were to create a dilution by adding water to a saltwater mixture, what would happen to concentration?
Concentration would decrease.
What is the force needed to exert 120Pa of pressure onto an area of 1.8m2?
216 N
When water is added to the ballast tank of a submarine, its density increases. This gives it:
Positive/Neutral/Negative Buoyancy?
Negative Buoyancy - it sinks!
Why does agitation (stirring) improve solubility?
Use the particle model of matter and density to describe why a hot air balloon floats.
Heating the air causes particles to move faster and further apart, which causes an increase in volume therefore decreasing density. The less dense hot air then floats above the denser, cold air outside the balloon.
If you poured a solution through a filter, what would happen? Why?
Nothing, the filter would not catch anything because the particles are fully dissolved.
Which substance is more viscous?
A - Moved 50cm in 62sec
B - Moved 73cm in 106sec
Substance B - flow rate of 0.69cm/sec
When you compress a container full of fluid:
-What happens to the density of the fluid?
-What does Pascal's Law state happens?
-Density increases
-The pressure is exerted equally throughout all the fluid
Describe the difference between: Independant variables, dependent variables, and controlled variables in a science experiment.
Independent - thing that gets changed.
Dependent - thing that changes in response
Controlled - things we keep the same