Density/Energy
If the density of substance A is greater than the density of substance B, will substance A float on substance B?
No - the substance with the lower density will float
Why do liquids have a definite volume but no definite shape?
Their particles are loosely bound but can slide past each other.
Define matter
Anything that has mass and takes up space
Which is not a chemical change? (Select all that apply)
A. Dissolving
B. Decomposing
C. Boiling
D. Corroding
A. Dissolving
C. Boiling
Where are all the places on the heating and cooling curve that a gas will be found?
D and E
Energy is given off when bonds are:
A. Formed
B. Broken
A. Formed
What type of property is density?
Physical property that doesn't change with amount (intrinsic)
An example of a substance that cannot be broken down any further by chemical means is:
A. salt
B. carbon
C. water
D. sugar
B. carbon
Chemical changes differ from physical changes because in chemical changes:
A. new substances are formed
B. properties change
C. a change in mass occurrs
D. less energy change takes place
A. new substances are formed
_________ is a measure of average kinetic energy
Temperature
How do you measure the volume of an irregularly shaped piece of metal?
Water displacement in a graduated cylinder
Are boiling point and freezing point chemical or physical properties? Why?
Physical - boiling or freezing a substance does not change it's chemical composition (does not change it to a new substance)
Two properties of water that would be most useful in identifying it are its:
a. mass and color
b. temperature and weight
c. freezing point and density
d. shape and size
c. freezing point and density
Two solutions are added together and produce a cloudy substance. What is the evidence that a chemical change has occurred?
Precipitate
Which section on the phase diagram represents a liquid?
C
A beaker has a mass of 34 grams. When the beaker is filled with 58 mL of a fluid it has a mass of 75 grams. What is the density of the fluid?
0.71 g/mL
Which of the following is a chemical property of magnesium?
A. Oxidizes to a white powder
B. Melts at 650 degrees C
C. Has a density of 1.74 g/mL
A. Oxidizes to a white powder
Why are the following not heterogeneous mixtures: salt, baking soda, air?
Salt and baking soda are compounds, air is a homogeneous mixture
What are the evidences of a chemical change that we remember with the mnemonic "Please Excuse Coughs Sneezes and Burps"?
Precipitate, Energy change, Color change, change in Smell, Bubbles
What is moving from a solid to a gas called?
Sublimation
Usually when a solid is heated, its volume increases. How does this increased temperature affect the density of the substance?
It decreases
In trying to identify a liquid compound, a student find that it has the same density, freezing point, and boiling point of a compound Z. Can the student reasonably assume that the liquid is in fact compound Z?
Yes - density, freezing point, and boiling point are often used to identify substances (they are intrinsic/intensive physical properties)
A sample of a pure white substance is heated and produces a reddish brown gas and leaves a brown residue in the test tube. The substance is most likely:
A. a solution
B. a compound
C. either an element or a compound
B. a compound
Which of the following is not a physical property of water:
Freezing point of 0 Celsius
Made of hydrogen and oxygen
Sugar dissolves in it
Made of hydrogen and oxygen (that is a chemical property)
What is the normal melting point of the substance shown in the phase diagram?
200 degrees C