Give me three examples of a characteristic property.
Density
Melting Point
Freezing Point
Boliling Point
100
How many significat digits are in the number below?
0.0333
two
100
Compare the masses of the three aluminum rods from Lab 3.2.
The were all within the unceratinity of the balance +-.02
100
Explain how we calculate density.
D=M/V
100
Give specific resaons why mass and volume cannot be used to determine whether an object is the same substance as another?
Mass and volume are not characteristic properties of a substance therefore it is difficult to use then to tell differences between substances.
200
Explain what density is.
The mass per unit volume of a substance.
200
In significant digits express your answer for 6.3/10.08.
64
200
Compare and contrast substances A and B in the 3.9 Freezing and Melting labs. Were they they same substances why/why not?
TOP solidified at about 83 degrees Celcius
BHT solidified around 70 degrees Celcius
Not they both had different freezing points
200
How would you distinguish between a freezing point of a subsatnce on a graph?
You would see a plateau as the substance cools.
300
Explain the melting point of a substance.
The point at which a solid turns to a liquid.
300
In significant digits express your answer for
1.55 x2.61x5.3.
21
300
Which of the following is the approximate ratio of the densiity of a gas from experiment 3.7 to the density of water (1.0g/cm3)
a. 1/100
b.1/10
c.10
d. 1/1000
The desnity of Carbon Dioxide was around 1.
The correct answer is 1/1000 D. Desnity of water is 1.0g/cm3
300
Does the desnity of a gas depend on how much gas is collected?
Density if a characteristic property of a substance so it does not depend on how much of that substance you have.
300
What can you conclude will happen to an object that is less dense than the liqiuid it is placed into?
The object would rise.
400
Explain the freezing point of a substance.
When a substance goes from a liquid to a solid.
400
In lab 3.7 the Density of a Gas why was it important to hold your hand over the mouth of the bottle while removing it from the water?
to make sure we got an accurate measurement of the gas collected through the experiment.
400
Explain what measurements and calculations you would need to find the density of a rectangular wood block/
You would need to measue the length, width and thickness of the block as well as the mass. You would multiply the length, width and thickness to get the volume and then divide the mass by the volume.
400
What is the range of densities for most solids and liquids? for gases?
between 0.5g/cm3 and about 20g/cm3 for solids and liquids.
1/1000 the densities of solid and liquids for gases.
500
In the examples below tell me the characterisitc properties of a substance.
a. sharp, heavy, shiny, stainless steel knife
b. small chunk of black tar
c. a beautifully carved wooden chair
a. stainless steel, shiny
b. black tar
c. wooden
500
Why are the additional digits provided by a calculator not significant?
Becausewe do not have the tools to measure to the billionth place and beyond. We have tools to measure to the hundreth and with gases to the thousanth
500
In lab 3.11 Boiling point did the boiling point depend on the amount of liquid? Explain what the difference in boiling points means.
No the amount did not matter and the difference in boiling points meant we had 2 different substances.
500
Object A has a mass of 500g and a density of 5.0g/cm3, object B has a mass of 650g and a density of 6.5 g/cm3. a.Which object will displaces the most liquid?
b. Could object A and object B be made of the same substance?
a. They will displace the same amount of liquid.
b. the different densities show they are made from different substances.
500
A parking lot is filled with automoblies.
a. does the number of wheels per automobile depend on the number of automobiles and why/why not?
b. Is the number of wheels per automobile a characteristic property of automobiles that distinguishes it from other vehicles?
a. No because every automobile has 4 wheels
b. yes because the number of wheels per automobile distinguishes it from other some other vehicles.