Download Midterm Review answers - Nutley Public Schools

NAME______________________
KEY_____________________________________________PERIOD_______________
MIDTERM REVIEW PACKET
1. Density:
A. Determine the density of an object with a mass of 42 g and a volume of 7.0 ml.
42g / 7.0 mL = 6.0 g/mL
B. Determine the volume of an object with a mass of 8.1 g and a density of 2.4 g/ml. 8.1 g/2.4g/mL = 3.38 mL
2. Safety:
a. A student gets a chemical on his hands then eats a chocolate bar. After he finishes the bar, he licks the melted
chocolate off of his fingers. What should he do?
Tell teacher. Consult the MSDS sheet regarding poisoning information. Apologize to his teacher for being a fool.
b.
Your partner spills a test tube of acid on her hand and starts to become hysterical. What should you tell her to do?
Calm down. Escort her to the sink to rinse her hand. Tell the teacher.
c. When should safety glasses be worn?
The entire time that the laboratory is going on, until your teacher tells you it is safe to remove them.
d.
Your partner lights a Bunsen burner without realizing that your big, droopy sleeve of your fuzzy sweater is very close.
Your clothes immediately catch fire. What should you do?
Stop. drop and roll to put out the fire. Or, use fire blanket. Tell teacher. Apologize to your teacher for neglecting to wear the
appropriate atture for lab!
3. States of Matter: Complete the following table.
STATE OF MATTER
SHAPE
VOLUME
(fixed or
(fixed or
varied?)
varied?)
SOLID
fixed
fixed
ENERGY
RANK
(1-most, 3least)
3
LIQUID
varies
fixed
2
GAS
varies
varies
1
DESCRIPTION OF PARTICLE
MOVEMENT
(rotation, vibration, translation)
vibration, rotation, translation (when
affected by outside force)
vibration, rotation, translation
vibration, rotation
4. What is the difference between weight and mass? Which is a more dependable measurement? Explain your answer.
Mass is the amount of matter in an object, while weight is the measurement of the effect of gravity on that matter. Mass is more
reliable, because it does not change with location
5.
Complete the following table:
DESCRIPTION / DEFINITION
matter that is made up of a single type of particle
SUBSTANCE
EXAMPLE
Neon atom
Water molecules
ELEMENT
matter that is comprised of a single type of atom only
hydrogen
HOMOGENEOUS MIXTURE
a mixture (combination of more than one type of
particle) which is uniform in consistency and
appearance
a mixture (combination of more than one type of
particle) which is NOT uniform in consistency and
appearance
coffee with cream and sugar
matter that is made of particles that are comprised of
more than one type of atom bonded together
NaCl or NH3
HETEROGENEOUS MIXTURE
COMPOUND
beach sand
6. Properties and Changes: Identify the following terms as one of the four (4) choices listed below.
PC – Physical Change
CC – Chemical Change
PP – Physical Property
CP – Chemical Property
1. Mass
3. Bending
5. Freezing Point
7. Color
9. Rusting
11. Hardness
13. Cutting
PP
PC
PP
PP
CC
PP
PC
2. Melting Point
4. Evaporation
6. Explosiveness
8. Condensing
10. Reactivity
12. Cooking
14. Density
PP
PC
CP
PC
CP
CC
PP
7. Basic Definitions: Define the following terms.
1. Chemistry
the study of matter, and the changes that it undergoes.
2. Mass
the amount of matter in something.
3. Energy
anything that can perform work
4. Scientific Theory
a supported hypothesis which explains the reasoning for phenomena
5. Scientific Law
this describes a pattern observed in nature
6. Hypothesis
tentative explanation for an observation in nature that is testable. Can be in “if, then, because”
format
anything that has both mass and volume
7. Matter
8. Imagine that a lab group measures the density of a sample of water. Keep in mind that the accepted density of water is
1.00 g/ml. Create data for each of the scenarios below (pretend that the group collected data from 3 separate trials.
Trial 1
Trial 2
Trial 3
1. Data that is both accurate
1.00
1.00
1.00
AND precise
2. Data that is just precise
0.50
0.50
0.50
but NOT accurate
3. Data that is neither precise 206
31
0.0002
NOR accurate
9. List 4 parts of Dalton’s Atomic Theory. Include his original statements and any changes that have been determined by
advances in studying the atom. If no changes have been made to his original ideas, indicate this in the space provided.
ORIGINAL THOUGHTS
MODERN DAY IDEAS
1. All elements are composed of tiny indivisible particles that
Today we know that atoms are divisible into protons, neutrons
are called atoms.
and electrons
2. Atoms of the same element are identical. The atoms of any
one element are different from those of any other element.
Today, we know that there are some differences between some
particles of the same elements such as ions and isotopes
3. Atoms of different elements can combine with one another
in simple whole number ratios to form compounds
This aspect has stood the test of time
4. Chemical reactions can occur when atoms are separated,
joined, or rearranged. However, atoms of one element are not
changed into atoms of another by chemical reactions
This actually can occur during nuclear fusion and fission.
10. Describe the discovery of the nucleus. By whom was it discovered and how?
Rutherford –gold foil experiment. Rutherford shot positively charged alpha particles at a thing sheet of gold. Some passed
through, others were deflected, and other ricocheted right back. The ones that bounced back or were deflected were interacting
with the nucleus.
11. Draw, label and describe the modern day model of the atom. Be sure to include all regions and subatomic particles and
the location of each.
12. Explain what information can be determined by the following:
a. Atomic Number:
the number of protons in the nucleus, and the number of electrons in a neutral atom
b. Mass Number:
the number of neutrons in an atom, as long as you know the atomic number
c. Atomic Mass:
the weighted average of the mass numbers of the different isotopes of an element
13. Complete the following table with the appropriate information.
ELEMENT/SYMBOL
ATOMIC
MASS #
#p+
#e#
Carbon
C
Calcium
Ca
Aluminum
Chlorine Cl
Al
#no
Nuclear
Symbol
6
13
6
6
7
13
20
40
20
20
20
40
13
27
13
13
14
27
17
37
17
17
20
37
14. What is the most important piece of information used to identify an element?
number of protons, which is the identifying characteristic of an element.
6
C
20Ca
13Al
17Cl
The atomic number, which tells you the
15. Fill in the table below with the indicated information regarding groups on the Periodic table.
Group
1A
2A
3A
4A
5A
6A
7A
8A
Name
Alkali
metals
Alkali
Earth
Metals
Boron
Group
Carbon
Group
Nitrogen
Group
Oxygen
Group
Halogens
Noble
Gases
Number of
Valence e-
1
2
3
4
5
6
7
8
Valance econfiguration
s1
s2
s2 p1
s2 p2
s2 p3
s2 p4
s2 p5
s2 p6
loses 1
loses 2
loses 3
n/a
gains 3
gains 2
gains 1
n/a
+1
+2
+3
n/a
-3
-2
-1
n/a
cation
cation
cation
anion
anion
anion
# e- lost or
gained
Charge of ion
(Cation or
anion?)
16. Write both the ELECTRON CONFIGURATION and ORBITAL NOTATION for the following examples
Element
Electron Configuration
Orbital Notation
Neon
1s2 2s2 2p6
↑↓ ↑↓ ↑↓ ↑↓ ↑↓
1s
2s
2p
Nitrogen
1s2 2s2 2p3
↑↓
1s
↑↓ ↑
2s
Fluorine
1s2 2s2 2p5
↑↓
1s
↑↓ ↑↓ ↑↓ ↑_
2s
2p
Lithium
1s2 2s1
↑↓
1s
↑__
2s
↑ ↑__
2p
17. Rank the following in order from the smallest to the largest: atom, electron, nucleus, molecule, proton
electron, proton, nucleus, atom, molecule
18. What is the difference between an ion and an atom? How AND why do atoms become ions?
Atoms # of protons = # of electrons, so they are neutral. This is not true for ions. Atoms become ions by gaining or losing
electrons, and they do they to achieve a full set of valence electrons, like a noble gas
19. Explain how an atom of magnesium is different from a magnesium ion.
a. What charge does a magnesium ion make?
+2 cation
b.
Why is this charge produced?
Magnesium loses two electrons
c.
Does magnesium become a cation or an anion?
cation
d.
Which is bigger, the Magnesium ATOM or the Magnesium ION. Explain why.
magnesium atom is bigger; the ion has lost electrons, so it has lost and entire energy level AND the protons now
outnumber the electrons
20. Explain how an atom of chlorine is different from a chlorine ion.
a. What charge does a chlorine ion make?
-1 anion
b.
Why is this charge produced?
Chlorine gains one electron so that it will achieve a full outer energy level
c.
Does chlorine become a cation or an anion?
anion
d.
Which is bigger, the Chlorine ATOM or the Chlorine ION. Explain why.
chlorine ion is bigger; the ion has gained electrons, so its electrons now outnumber its protons. Electrons will also
repel each other a spread out.
21. A. What is an isotope?
This is an atom of a given element that differs in the number of neutrons
B. What two bits of information must be known in order to calculate the average atomic mass for an element?
The mass numbers of the isotopes, and the percent abundance of each
C. Use the following information to calculate the average atomic mass for the element Copper.
Cu-63, 69.1% abundance
Cu-65, 30.9% abundance
(63 x 0.691 ) + (65 x 0.309) = 43.533 + 20.085 = 63.6 amu
22. What charge will the following ions make?
1. F
-1
2. All group 3 elements
+3
3. Na
+1
4. An atom that loses 2e-
+2
5. An atom that gains 1e-
-1
-3
7. All group 6 elements
-2
9. An atom with an electron
configuration of 1s22s22p63s2
+2
6. An atom with 5 valence
electrons
8. An atom with 2 e- in its
outermost energy level
10. All alkaline earth metals
+2
+1
23. Write the formula for the following compounds on the first line. Indicate whether each compound is ionic (I) or
covalent (C) on the second, shorter line.
a. Calcium nitrate __Ca(NO3)2__, __I___
b. Lithium nitride _______Li3N________, __I___
c. Tin (IV) chloride ____SnCl4__, __I__
d. Trinitrogen tetroxide ___N2O4________, ___C__
e. Sulfur dioxide ____SO2_____, __C___
f. Aluminum hydroxide ___Al(OH)3_____, _I____
24. Name the following compounds. Indicate whether each compound is ionic (I) or covalent (C) on the second, shorter
line.
a. S3F6 ____Trisulfur hexafluoride, __C___
b. Na2SO4 _Sodium sulfate, ___I__
c. P2O5 _____Diphosphorus pentoxide, ___C__
d. Al2O3 _Aluminum oxide, __I___
e. Ca3(PO4)2 ___Calcium phosphate, __I___
f. Fe2O3 ___Iron (III) oxide, ___I__
25. Fill in the table concerning properties of ionic vs. covalent compounds.
Type of Compound
General Characteristics
Formed by metals, nonmetals or both?
Ionic Compounds
high boiling points and melting
points, crystals, solids,
metals and non-metals
electrolytes
Covalent Compounds
can be solid, liquid or gas,
non-metals and other
insulators, brittle, nonnon-metals
electrolytes
Reason for characteristics
ionic bonds form network
solids, where each ion is
bound to many others
while the bonds within
molecules are strong, the
attractions between molecules
may only be slight
50. What is the molar mass of:
a. NaCN
[Na (1 x 22.990g) + C (1 x 12.011g) + N (1 x 14.007g)] = 49.008g/mol
b. Na2SO4 [Na (2 x 22.990g) + S (1 x 32.065g) + O (4 x 15.999)] = 142.041g/mol
c. Al(C2H3O2)3 [Al (1 x 26.982g) + C (6 x 12.011g) + H (3 x 1.0079g) + O (6 x 15.999)] = 198.0657g/mol