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MATTER
ATOMIC THEORY
CHEM REACTIONS
ACID BASE
MISC
100
What is the difference between an element and a compound? Give a specific example of each.
An element is the simplest form of matter that has a unique set of chemical/physical properties. H, O, C, N A compound is a substance that contains two or more elements chemically combined in a fixed ratio: H20, CO2, CO, CH4
100
Most of an atom is made up of... but the two subatomic particles in the nucleus are ..... and ...
EMPTY SPACE....PROTONS...NEUTRONS
100
Name the 5 types of chemical reactions, DEFINE THEM, and write them out using letters, A,B, C, D
Combination: Two elements or compounds make a single product A + B -> C Decomposition: A single compound splits into two or more elemental products AB --> A + B Single-Replacement: An element and a compound replace another element, producing another element and a compound A + BC --> C + AB Double Replacement: Two ionic compounds exchange cations, forming two new compounds AB + CD --> AC + BD Combustion: oxygen and a hydrocarbon react to produce carbon dioxide (or CO if complete combustion) and water Hydrocarbon + O2 --> CO2 + H2O
100
Name 3 properties of Acids.
Taste sour like lemons strong/weak electrolytes (can conduct electricity as ions) Give up H+ according to BL definition Ionize to yield H+ according to Arrhenius
100
What is the difference between empirical formula vs. molecular formula? Give a specific example.
An empirical formula is the lowest whole number ratio of atoms in a formula that cannot be reduced any more like CO2 or H2O A molecular formula may be the same as the empirical formula or a whole number multiple, like C2O4 or H4O2
200
A change that produces matter with a different composition than the original matter is called.....
A chemical change/reaction
200
Calculate the number of neutrons in one atom of electrically neutral Neon.
Neon mass number =20 (N+P) - 10P = 10 N
200
After wood burns, the ash has a mass that is much less than the original wood. Explain why the law of conservation of mass is not violated.
Because gas is given off in the form of carbon dioxide in this combustion reaction and water is created as well. So the mass of ALL products is the same as the mass of the original reactant.
200
What is the generic chemical formula for a neutralization reaction?
Acid + Base --> Salt (ionic compound) + WATER
200
Explain the difference between accuracy and precision.
Accuracy- your number is close to a standard or accepted value or to the bulls eye Precision- multiple numbers are highly consistent, close in value to one another, or clustered together
300
Categorize the following as Heterogeneous (not uniform, more than one phase) vs. Homogeneous (one phase, smaller particles) mixtures. 1. salad dressing 2. trail mix 3. a bronze copper alloy 4. chicken noodle soup
1. homogeneous 2. heterogeneous 3. homogeneous 4. heterogeneous
300
How do isotopes of an element differ? Name 2 ways.
Isotopes of an element have 1) different numbers of neutrons 2) different mass number (N+ P)
300
Balance the following chemical equation: FeCl3 + NaOH --> Fe(OH)3 + NaCl
1, 3, 1, 3
300
Calculate the pH of a solution with an [OH-] of 0.0003.
-log (0.0003)= pOH= 3.522 pH+ pOH= 14 14- pOH= pH 14-3.522= 10.5 pH
300
Put this # into scientific notation. 0.0000945
9.45 x 10-5
400
In what way are liquids and gases alike? In what way are liquids and solids different?
Liquids and gases are both compressible and can take the volume of a container. Particles of both liquids and gases are free to flow/move past one another and are spread out. Liquids and solids are different because solids have tightly packed particles in a rigid arrangements. Solids have a definite shape and volume, and are incompressible. Solids expand only slightly when heated. Liquids can flow past one another, and have indefinite shape but fixed volume. They expand slightly when heated.
400
Calculate the average atomic mass of element X, if X-10 is 19.91% abundant and X-11 is 80.09% abundant.
10.81 amu 10 x 0.1991 =1.993 amu 11 x 0.8009= 8.817 amu
400
Write the electron dot diagrams for the following elements. Remember the electron dot diagrams show the number of valence electrons of that element. Li Br Kr Al
Br- 7 Kr- 8 Al-3
400
What are the units for [H+] or [OH-]?
Molarity or M. Moles/Liter
400
What is the length of a spine on a diatom in cm if it is 46 nanometers?
nanometers--> meters --> centimeters 4.6 x 10-5 cm
500
Describe a procedure to separate a mixture of sand and table salt and water.
Use filter paper to filter out the sand grains. Then boil the water off (evaporate) to leave the salt in solid form.
500
Write the hyphen and nuclear notation for an atom of Sulfur.
32 (upper number, #P + N) 16 (lower number, #P) S
500
What is the difference between sub-scripts and coefficients when balancing a chemical reaction?
Can change the coefficients which represent the molar ratios but CANNOT change the sub-scripts (tiny little #s) that represent the number of atoms of each element in a compound
500
Write the chemical equation for the combination of water with HCl--> What is the Acid, Base, Conjugate Acid, and Conjugate Base
H2O + HCl --> H3O+ + Cl- B A CA CB
500
Define the following metric system measuring units: VOLUME MASS WEIGHT TEMPERATURE
VOLUME- amount of space in an object MASS- amount of matter in an object WEIGHT-a force that measures the pull on a given mass by gravity TEMPERATURE- how hot/cold an object is, determined by molecular motion called kinetic molecular theory