Density
What is the equation to solve for density?
D = m/v
What are two types of pure substances?
Elements and Compounds
What is a physical property of water?
B.P. , M.P, state of matter, viscosity, etc.
When a salt water solution completely evaporates, the residue left in the container is a(n)_________.
compound
Is rusting a physical or chemical change?
Chemical
What are the two accepted units for density?
What is the density of water (with units)?
g/mL and g/cm3
1 g/mL or 1 g/cm3
What are the two types of mixtures?
Homogeneous and Heterogeneous
List if the following properties are physical or chemical.
1. Boiling pt
2. Flammability
3. Reactivity with strong base
4. Color
1. BP is physical
2. Flammability is chemical
3. Reactivity is chemical
4. Color is physical
How do you calculate % concentration?
Use the nutritional value of the solution and the provided density of the sugar. Use the following formula: 35/355 X 1/2.22 = ____ X 100
The dimensions of a metal cube are 5 cm X 5 cm X 5 cm with a known density of 5.66 g/cm3. What is the mass of the metal cube?
708 g
You have a 45 g rock with a volume of 15 cm3. What is the rock's density?
D = 45/15 = 3.0 g/cm3
Water H2O, NaCl, etc.
Describe the difference between physical and chemical changes.
Physical changes do NOT change the chemical composition. Chemical changes DO change the chemical composition.
A drink has a density of 2.60 g/mL. According to the nutritional value, it contains 46 g of sugar per a 355 mL serving. What is the % sugar concentration in the drink?
46/355 X 1/2.60 = .0498 X 100 = 4.98%
List 3 extensive properties.
mass, volume, length
The density of pure solid copper is 8.94 g/mL. What volume does 5.00 kg of copper occupy?
D = m/v
8.94 = 5000./v
v = 559 mL
What type of substance can ONLY be separated by chemical means?
Compounds
List the following as intensive or extensive properties
1. Boiling point
2. Mass
3. volume
4. Flammability
1. intensive
2. extensive
3. extensive
4. intensive
A rock was placed in 10 mL of water in a graduated cylinder. The water rose to 38 mL. What is the volume of the rock?
38 - 10 = 28 mL
A student measured the density of water to be 1.66 g/mL. What is the percent error?
1.66 minus 1.00 / 1.00 = 0.66 X 100 = 66% error
A golden-colored cube is handed to you. The person wants you to buy it for $100, saying that it is a gold nugget. You pull out your old geology text and look up gold in the mineral table. Shows that gold's density is 193 g/cm3. The cube is 2 cm3 on each side, and has a mass of 40 g. What is its density? Is it gold? Should you buy it?
D = 40/8 = 5 g/cm3
No
Do NOT buy it!
What is the difference between a pure compound and a homogenous mixture?
Give an example of each.
A pure compound is composed of two or more elements (bonded together) in a uniform manner.
A homogeneous mixture is composed of a multiple variety of solutions in a random, non-uniform manner.
Which of the following is a physical property?
A. Density
B. Oxidation
C. Flammability
D. Reactivity
Density
A chemist has measured 8.25 kg of a sample on the triple beam balance. How many milligrams does this represent?
8,250,000 mg
List 5 ways to know that a reaction has taken place.
Change in temperature
Change in color
Odor
Formation of a precipitate
Formation of bubbles