Benchmark Mid-Term Study Guide

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Benchmark Mid-Term Study Guide
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Chapter 1 Introduction to Chemistry

• A systematic approach that scientists use
• Scientific method

• 1. Observation
• 2. hypothesis
• 3. experiment
• results/Data
• Conclusions
• 6. theory
• 7. law

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Matching
B

• ___ 6. refers to physical characteristics such
  as color, odor, or shape
• ___ 7. refers to mass, volume, and temperature
  measurements
• ___ 8. a variable controlled by the
  experimenter
• ___ 9. the act of gathering information
• ___ 10. changes in value based on the value of
  the controlled variable
• a. Observation
• b. Qualitative data
• c. Quantitative data
• d. Independent variable
• e. Dependent variable

C
D
A
E
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Multiple Choice

• A constant is a factor that
• a. Changes during an experiment
• b. Changes from one lab group to another
• c. Is affected by the dependent variable
• d. Is not allowed to change during an
• experiment

5
Matching

• A control is
• a. Variable that changes during an
• experiment
• b. Standard for comparison
• c. Type of dependent variable
• d. Type of experiment

6
Matching

• A hypothesis is a(n)
• a. Educated Guess
• b. Explanation supported by many
• experiments
• c. Tentative explanation of
• observations
• d. Law describing a relationship in
• time

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Matching

• A theory is a(n)
• a. Set of controlled observations
• b. Explanation supported by many
• experiments
• c. Tentative explanation of
• observations
• d. Law describing a relationship in
• time

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Matching

• A law is a(n)
• a. Set of controlled observations
• b. Explanation supported by many
• experiments
• c. Tentative explanation of
• observations
• d. Law describing a relationship in
• time

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Matching

• A model is a(n)
• A visual, verbal, or mathematical.
• GRAPH, Pie Chart

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Completion

1. What piece of lab equipment should be used to
   accurately measure volume?
2. What piece of lab equipment should be used to
   accurately measure mass?
3. What is the proper technique for smelling a
   chemical in the laboratory?
4. What is the proper technique for holding a test
   tube while heating?

Graduated cylinder
Balance
Wafting
Test tube holder
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Chapter 2 Data Analysis

• Change the following data into scientific
  notation.
• a. 5,000,000 km
• b. 0.000421 g
• c. 0.03 cm

5 x 106 km
4.21 x 10-4 g
3 x 10-2 cm
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• Change the following data into ordinary notation.
• a. 5.3 x 1012
• b. 4.0 x 105
• c. 6.1 x 10-5

5,300,000,000,000
400,000
0.000061
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• 3.Use the terms precise and accurate to describe
  the following figures. You may use both terms for
  some figures. If a term does not apply to a
  figure, leave the space blank.

neither
Precise but Not accurate
Accurate precise
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• Students were asked to find the density of an
  unknown white powder. Each student measured the
  volume and mass of three separate samples. They
  reported calculated densities for each trial and
  an average of the three calculations in the
  following data table. The power was sucrose,
  also called table sugar, which has a density of
  1.59 g/cm3.
• a. Which students measurements were most
  accurate?
• b. Which students measurement were most
  precise?

A because all of their values are close to the
accepted value of sugar, 1.59
C because all of their values are close
together but not close to the accepted value
Density Data Collected by Three Different Students Density Data Collected by Three Different Students Density Data Collected by Three Different Students Density Data Collected by Three Different Students
Student A Student B Student C
Trial 1 1.54 g/cm3 1.40 g/cm3 1.70 g/cm3
Trial 2 1.60 g/cm3 1.68 g/cm3 1.69 g/cm3
Trial 3 1.57 g/cm3 1.51 g/cm3 1.71 g/cm3
Average 1.57 g/cm3 1.51 g/cm3 1.70 g/cm3
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• 5. A sample of aluminum is placed in a 25 mL
  graduated cylinder containing 10.0 mL of water.
  The level of water rises to 18.0 mL. Aluminum
  has a density of 2.7 g/mL. Calculate the mass of
  the sample. (Use appropriate significant
  figures.)

• 18.0 mL m d(v)
• 10.0 mL 2.7 g/mL(8.0mL)
• 8.0 mL 21.6g 22g

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• 6. You have a 230g sample of ethanol with a
  density of 0.7893 g/mL. What volume of ethanol
  do you have? (use appropriate significant figures)

v m/d 230g 0.7893g/mL
291.4 290 mL
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• 7. An object with a mass of 7.5g raises the
  level of water in a graduated cylinder from 25.1
  mL to 30.1 mL. What is the density of the object?

• 30.1 mL d m/v 7.5g
  1.5 g/mL
• 25.1 mL 5.0mL
• 5.0 mL

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• Determine the volume indicated in Figure 1.
• Determine the length indicated by Letter H in
  Figure 2.
• 10. Determine the volume indicated in Figure 3.

64.0 mL
12.94 cm
34.7 C
Figure 3
Figure 1
Figure 2
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Chapter 3 Matter Properties Changes
mass

• Matter is anything with (1) ____________________
  and volume. A (2) ____________________ is a form
  of matter with a uniform and unchanging
  composition. Substances have specific,
  unchanging (3) ____________________ that can be
  observed. Substances have both physical and
  chemical properties. (4) ____________________
  properties can be observed without changing a
  substances chemical composition. Color,
  hardness, and (5) ____________________ are
  examples. Other properties cannot be observed
  without changing the composition of a substance.
  These are called (6) __________________
  properties. An example is the tendency of iron
  to form rust when exposed to air.

substance
properties
physical
density
chemical
chemical mass physical
density properties substance
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• Label each property as either physical intensive,
  physical extensive, or chemical.

7. Bitter taste 8. length
9. Corrosion 10. Malleability
11. Magnetic 12. Flammability
13. Volume 14. Reacts with an acid to form a gas
Physical-intensive
Physical-extensive
Physical-intensive
Chemical
Physical-intensive
Chemical
Physical-extensive
Chemical
Intensive doesnt matter how much you
have Extensive does matter how much you have
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• _____ 15. A solid has definite shape and volume.
• _____ 16. A liquid has a definite shape and
  takes on the
• volume of its container.
• _____ 17. A gas has both the shape and the volume
  of its
• container.
• _____ 18. The particles in a solid are spaced far
  apart.

True
False
True
False
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gas
solid
liquid
19. ____________
20. ____________
21. ____________
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• What are the four indicators that a chemical
• change has taken place?

a. Temperature change
b. Color change
c. Gas (bubbles) produced
d. Precipitate (solid) formed
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• Identify the following as physical or chemical
  changes

23. Log burning 24. Making kool-aid
25. Iron rusts in air 26. Fermentation of apple juice
27. Milk sours 28. Slicing bread
29. Water boiling 30. Dissolving NaCl into H2O
P
C
C
C
P
C
P
P
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Solution Colloid Suspension
Size of particles Too small to see
Composition Heterogeneous
Tyndall effect Negative
Settle Out No
Clarity Cloudy
intermediate
visible/large
homogeneous
heterogeneous
positive
negative
No
Yes
Clear
Cloudy
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Type of Matter Substance Mixture
Water
Soil
34. Sugar water
Oxygen
36. Carbon dioxide
Rocky road ice cream
compound
heterogeneous
homogeneous
element
compound
heterogeneous
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• List four techniques that can be used to separate
  a mixture.

1. Filtration
2. Distillation
3. Chromatography
4. crystallization

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Chapter 4 The Structure of the Atom
Subatomic particle Location Charge Relative Mass
Proton
Electron
Neutron

1
Inside nucleus
Outside nucleus
-
0
1
0
Inside nucleus
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1. Most of an atoms mass can be found in the
   ______________.
2. The number of protons in an atom is its
   ________________.
3. The number of protons neutrons in an atom is
   its ______________.
4. In a neutral atom, the number of ______ always
   equals the number of __________.
5. Isotopes are atoms of an element with a different
   ________. They have the same number of ________
   but a different number of ____________.

nucleus
atomic
mass
protons
electrons
mass
neutrons
protons
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• Use a periodic table to identify the following
  elements.
• a. 47 protons
• b. 95 electrons
• c. Atomic number 28
• d. 6 protons and 8 neutrons

Ag - silver
Am - americium
Ni - nickel
Carbon 14 or 14 6
C
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Isotope Name Symbolic Notation Number of Protons Number of Electrons Number of Neutrons
Oxygen16
N 7
35 45
16 8
O
8
8
8
7
9
Nitrogen - 16
80 35
35
Br
Bromine - 80
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• 9. Three isotopes of argon occur in nature
  Ar, Ar, and Ar. Calculate the average
  atomic mass of argon to two decimal places, given
  the following relative atomic masses and
  abundances of each of the isotopes argon36
  (35.97 amu 0.337), argon38 (37.96 amu
  0.063), and argon40 (39.96 amu 99.600).

36 18
38 18
40 18
35.97 (0.00337) 0.1212 37.96 (0.00063)
0.0239 39.96 (0.996) 39.800
39.945 amu
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Chapter 25 Nuclear Chemistry
Radioactivity Process where substances emit radiation
Radioisotopes Unstable isotopes that are radioactive
Half-life Time required for one-half of a radioisotopes nuclei to decay into its products
Nuclear fission Splitting of a heavy nucleus into two smaller nuclei (nuclear power plants)
Nuclear fusion Combining two nuclei to form a heavier, more stable nucleus occurs in the sun
2. Nuclear reactions involve changes in an
atoms nucleus, whereas chemical reactions do not.
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Type of radiation Symbol What is it? Can be stopped by Penetrating Power
Alpha, a a Particle Paper
Beta, ß ß Particle Wood/ aluminum foil
Gamma, ? G wave Lead/ concrete
4 2
He
0 -1
e
energy