Download Chemistry Midterm Review

Chemistry Midterm Review
Name_________________________
Block#_________
Chapter 1 Matter, Changes and Energy
Chemistry is defined as the study of the ____________of matter and the __________ it undergoes.
Matter is defined as anything that has __________ and takes up _________.
Mass is a measure of the amount of ________ an object contains.
Matter exists in three states:
1) ___________ which has a definite shape and definite volume.
2) __________ which has an indefinite shape but definite volume
3) __________ which has an indefinite shape and indefinite volume
Matter can be classified as either:
- ________ _________ which cannot be separated into simpler substances by physical methods.
Or
- _____________ which can be separated into simpler substances by physical methods
such as filtering, settling, evaporating, boiling, etc..
Pure Substances can be classified as either:
- ______________ which are the simplest forms of matter and act as the building blocks for all other
substances. The smallest particles with all the properties of this material are called
Or
_________.
EXAMPLE:___________
- ______________ which are chemical combinations of two or more of the building blocks and have
properties much different than the building blocks from which they are formed. The
smallest particle with all the properties of this material is called a _______________.
EXAMPLE:_____________
Mixtures are physical blends of materials which can be classified as either:
- ___________________ which means that the composition is uniform throughout. All samples of this
type of mixture would have the same ratio of components. A mixture of this
Or
type is also known as a __________. EXAMPLE___________
- __________________ which means that the composition is not uniform. Every sample
of this type of mixture would have a different ratio of
components. EXAMPLE:__________
Identify the following as a homogeneous mixture (HOM), a heterogeneous mixture (HET), a compound ( C ) or an
element ( E ).
A. Copper __________
B. Air __________
C. Sugar _________
D. Salt water _________
E. Water ________
F. Apple juice _______
All matter has two types of properties:
- ________________ which are descriptive qualities or conditions of a substance which
can be measured without changing the composition of the
Or
` substance. EXAMPLES:_________, __________, __________
- _______________ which are a measure of a substance’s ability to change its composition
or its identity. EXAMPLES:_________, __________
Identify the following as Physical properties ( P ) or chemical properties ( C ).
A. Color ________
B. Size _________
C. Flammability __________
D. Reactivity _________
E. Shape _________
F. Explosiveness __________
All matter can undergo two types of changes:
- ______________ which are typically a change in a substance’s appearance but not its
identity. EXAMPLES:_________, __________, __________
- ______________ which result in the change of a substance’s composition and identity.
EXAMPLES:_________, __________, __________
Identify each of the following as either a physical change ( P ) or a chemical change ( C ).
A. Iron Rusts _________
B. Alcohol evaporates ________ C. Milk sours _________
D. Coal burns _________
E. Ice melts ________
F. Sugar dissolves in water_________
The changes that matter undergoes can be written in the form of a chemical equation which is a short hand
representation of the reaction using chemical and other symbols.
Define the following symbols used in writing a chemical equation:
“+”
“”
(s)
(g)
(aq)
“”
(l)
A chemical reaction that releases heat is said to be: ______________________
A chemical reaction that absorbs heat is said to be: ______________________
The scientific method is a systematic way of solving problems.
List and define the steps in the scientific method.
1.________________________________________________________________________________
2.________________________________________________________________________________
3.________________________________________________________________________________
4.________________________________________________________________________________
5.________________________________________________________________________________
Chapter 2: Scientific Measurement
Information (data) which is collected about a substance or a reaction can be of two types:
- __________________ which is information that is descriptive in nature and uses relative terms in
its descriptions. For example: tall/short, high/low, old/young, large/small
- __________________ which is information that is specific in nature and uses numbers in its
descriptions. For example: 29 oC, 34.6 mm, 17 years old
Indicate whether each of the following descriptions is Qualitative (Qual) of Quantitative (Quan)
A. Hot ________
B. 35.8 ft __________
C. Soft __________
D. 90 g _________
E. 2.76 hrs __________
F. Dark __________
Different tools are used to collect data in four major categories (mass, length, volume, temperature.
Identify which type of data(Mass, Length, Volume, Temp) can be collected using each of the
following tools
A. 12 inch ruler _________
B. Thermometer __________
C. Triple-beam balance _________
D. Meter Stick _________
D. Graduated Cylinder _________
E. Measuring Cup _________
The quality of measurements can be evaluated in two ways:
- ________________ which is a measure of how close an experimental answer is to a true answer
- ________________ which is a measure of how repeatable a series of measurements are.
The metric system is part of the SI system and uses a series of prefixes to show by how many factors of 10 a
measurement is larger or smaller than a base unit. The base unit is established relative to a commonly accepted
standard.
Base Units:
Length = __________
Mass = __________
Volume = _________
Prefixes (Decimal Multipliers)
Prefix
Abbreviation
Decimal Multiplier
Base (g, m, L)
DRUL RULE
Make the following conversions
A) 35.3 cm = __________ km
B) 0,077 mg = __________ g
C) 140 hL = __________ daL
E) 22.7 L = __________ mL
D) 14,000 dm = __________ mm
F) 25.9 kg = ___________ mg
G) 0.0007 m = ________ cm
H) 92.1 dL = _________ kL
Sometimes measurements can be combined to create new measurements called derived measurements. An example
of a derived measurement is the term density which is a ratio of the mass to the volume of a substance and can be
used for identifying a substance.
Density (D) =
(M)
----------------(V)
The typical units used for density are g/mL or g/ cm3.
Solve the following density related problems
A.. A sample of copper has a mass of 44.5 g and occupies a volume of 5.00 cm 3. What is its density?
B. A sample of a liquid with a density of 4.75 g/ml has a volume of 23.1 mL. What is the mass of the
sample?
C. The following data was collected by a group of students who were trying to determine the density of a
metal bar.
What is the density of the metal?
length = 10.0 cm
Mass of bar = 480.00 g
width = 4.00 cm
height = 3.00 cm
Chapter 4: Atomic Structure
The idea of an indivisible particle in all matter, the “atomus”, was first suggested in the 4 th century B.C. by the
philosopher, ________________.
This concept was lost for many centuries until the work of several scientists made key discoveries and presented
increasingly sophisticated models for the atom.
Match the scientist with his key contribution to the model of the atom. Some may be used more than once.
1. Dalton
2. Thomson
3. Rutherford
4. Bohr
A. Proposed the “Plum-pudding” Model _________
D. Stated electrons must travel in defined orbits _________
B. Proposed the 1st Atomic Theory
_________
E. Discovered the electron
C. Discovered the nucleus
space_________
_________
F. Determined that most of the atom is empty
The atom is now known to consist of three major, subatomic particles. They are:
- ______________ (symbol =
surrounding the
) These are negatively charged particles which are found in the orbits
atom’s central core.
- ______________ (symbol =
of the atom
) These are positively charged particles which are found in the central core
known as the nucleus.
- ______________ (symbol =
) These are neutral particles that are also located in the nucleus of the
_________
atom.
Terms related to atomic structure
- ________________ tells the number of protons located in the nucleus of an atom of this element.
- ________________ tells the number of protons + number of neutrons in the atom.
- By subtracting the _______________ from the _____________ we can determine the number of
neutrons in an atom.
- The number of electrons in a neutral atom is equal to the number of ___________ in the atom.
- _________________ is the abbreviation for atomic mass unit which is used for measuring the
mass of a subatomic particle. p+ & no = 1 amu each. e- = 1/2000 amu
Please complete the following table using the periodic table as needed:
Element
Symbol
Atomic #
Mass #
# of p+
# of e-
# of no
Sodium
Ta
76
82
80
- ________________ are atoms of the same element with the same number of protons but a different
number of
neutrons.(i.e. same Atomic # different Mass #)
- ________________ is the weighted average of all the naturally occurring isotopes of an element.
To calculate the atomic mass we multiply the mass of each isotope by its abundance and then add the masses
together to get the atomic mass.
EXAMPLE: Chlorine consists of two isotopes Cl- 35 (75% abundance) & Cl-37 (25% abundance.)
35 amu x .75 = 26.25 amu
37 amu x .25 = 9.25 amu
------------Atomic mass = 35.50 amu
Solve the following problem
The element silver has two naturally occurring isotopes:
Silver-107 (52%)
Calculate its average atomic mass.
Silver-108 . (48%)
(107.48 amu)