Name:
UNIT-I
Chemsitry-1
1. Matter
2. Energy
Designing Experiments
Vocabulary
Independent variable:
Dependent variable:
Multiple trials:
Comparision
Independent
Dependent
Fill in the Blanks
Chemist
Hypothesis
potential energy
value judgment
Chemistry
inertia
Radiant energy
Energy
kinetic energy
science
fact
matter
sulfuric acid
1. ________________________ is the science of materials and the changes they undergo.
2. ________________________ is a property possessed by all matter, which under the proper
conditions can be used to do work.
3. ________________________ deals with determining facts about the physical universe.
4. ________________________ is energy passing between objects separated by empty space.
5. ________________________ is the resistance of matter to changes in either the direction or the rate
of its motion.
6. ________________________ refers to the motion of one object with respect to another.
7. A(n) ________________________ investigates the interrelationship between the properties and
structures of materials.
8. All ________________________ has inertia.
9. ________________________ depends on the position of one portion of matter with respect to
another portion.
10. A(n) ________________________ is an estimate based on observations.
11. A(n) ________________________ involves comparing an occurrence with your own set of
standards.
12. A(n) ________________________ is an actual occurrence.
Chemical and Physical Changes
Changes that produce new kinds of matter with different properties are called chemical
changes. Changes that do not do so are called physical changes. Classify each of the following as
either a physical change (P) or a chemical change (C).
A. boiling
_____
B. iron rusting _____
C. tearing _____
D. freezing _____
E. grinding _____
F. mixing _____
G. burning _____
H. electrolysis _____
I. distillation _____
J. decomposition _____ K. melting _____
M. alcohol
evaporation _____
N. baking
a cake _____
Q. wood rotting _____
R. glass breaking _____ S. cutting grass _____
O. magnetizing
a nail _____
L. butter melting _____
P. leaves
changing color_____
Complete the following sentences by filling in the appropriate word from the list
below. Each word can be used once, more than once or not at all.
chemical
electrolysis
gas
solid
chromatography
energy
liquid
physical
crystallization
evaporation
matter
plasma
distillation
filtration
physical means
1. Heterogeneous mixtures are often separated by ______________ ____________.
2. Separating sand from water can be done by ______________________.
3. The sugar in sugar water can be separated by ______________________.
4. The separation technique that takes advantage of differences in boiling points is called
_______________.
5. Removing chlorophyll pigment from leaves might be done by ______________________.
6. The best way to decompose water into oxygen and hydrogen is by ______________________.
7. Crude oil is broken down by heat, vaporized, and allowed to condense into various liquids such as
gasoline. This process is called ______________________.
11. _______________ changes alter the identity of a substance whereas _______________ changes do
not.
13. Could distillation be used to separate air into oxygen, nitrogen, carbon dioxide and so forth?
Explain.
14. Why is every solution a mixture, but not every mixture a solution?
15. Why are milk and paint often thought to be homogeneous mixtures but are actually heterogeneous?
16. What is the relationship between the kinetic energy of molecules and their physical state?
17. How would you determine if a change in matter is a physical or a chemical change?
18. What properties do glass and plastic share that allow them to be substituted for each other in some
applications? What properties do glass and plastic have that make them quite different
This starts with the golfer squeezing the trigger with his finger (Ex). The pistol’s hammer hits the firing cap (#1). The firing cap ignites the gunpowder (#2), releasing heat (#3) as a byproduct. The tee fires into the ground. The noise from the gun (#4) causes nerves to fire in the groundhog’s brain (#5) causing it to dive into the hole (#6). This pulls the cord around its neck, disrupting the resting bowling ball (#7). The ball falls (#8), squeezing the bulb, forcing air (#9) through the atomizer. This wets the shirt, causing it to shrink, releasing the held ball (#10). The ball falls on to the tee (#11). Label the steps of the complicated machine above as Kinetic or Potential. Then whether it’s Chemical, Electrical, Mechanical, Gravitational, Light, Sound, Thermal, or Wind: Potential (P) or Kinetic (K) One Type (as above) Ex. Mechanical 1. K 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. Questions: 1. Classify each as kinetic (K) or potential (P) energy: a. skateboard at the top of a hill b. charged battery c. rolling bowling ball d. gallon of gasoline e. waterfall 2. Give the following Energy Conversions: a. Charging a Chemical Battery from a wall outlet b. Lifting a large weight c. Travelling on a Bicycle 5. Types of Reactions
Endothermic:
Exothermic:
Energy and Chemical Change
Choose words from the word list to fill in the blanks in the following paragraphs relating to energy
and chemical change. The list pairs words that have contrasting meanings.
absorbed/released
exothermic/endothermic
can/cannot
heat
chemical change(s)
light
electrical
Energy is observed to accompany ____________ ____________ in the form of heat, light, and
electricity. Chemical energy stored in natural gas (mostly methane, CH4) is __________________ in
the form of __________________ and __________________ when the gas burns in the presence of
oxygen. Chemical energy stored in an automobile battery is __________________ in the form of
__________________ energy when the engine is started.
During ____________ ____________ energy may be readily converted from one form to
another. Energy __________________ be destroyed in a chemical reaction. There is a net release of
energy when more energy is __________________ during the reaction than is __________________.
Reactions showing a net release of energy are called __________________ reactions. There is a net
absorption of energy when more energy is __________________ during the reaction than is
__________________. Reactions showing a net absorption of energy are called
__________________ reactions.
For each of the following changes state whether the change is endothermic (endo) or exothermic (exo).
A. boiling of water ______
B. burning of charcoal ______
C. formation of frost ______
D. evaporation of water ______
E. production of sugar by plants ______
F. burning of steel wool ______
G. burning of natural gas ______
H. drying clothes ______
Energy Conversion :
Convert the following temperatures:
1) 573oC = ? K
5) 18 oC = ? K
_______________
2) 0 K = ? oC ________________
6) 1286K = ? oC
_______________
3) -86 oC = ? K
________________
7) 26.4K = ? oC
_______________
4) 273K = ? oC
________________
8) 100 oC = ? K
_______________
________________
Review
Pure Substances and Mixtures
solute
homogeneous
elements
compounds
mixture
phase
matter
solution
1. A physically separate part of a material with a uniform set of properties is a(n) _____________.
2. The dissolved material in a solution is the ______________.
3. _____________ are substances, such as pure salt or pure sugar, that always have elements chemically
combined in the same proportion.
4. ______________ is anything that takes up space and has mass.
5. A(n) _______________ is homogeneous matter composed of more than one material.
6. Substances composed of only one kind of atom are called _______________.
7. _______________ materials are those consisting of only one phase.
Concept Review. Classify the following materials as to whether it is a pure substance or a mixture. If it is a
pure substance, write E (Element) or C (Compound) in the Pure Substance column. If it is a mixture, write H
(Heterogeneous) or S (Solution, which is the same as a homogeneous mixture) in the Mixture column. The first
one is done for you.
Type of Matter
1. soil
2. water
3. oxygen
4. sugar water
5. carbon dioxide
6. Clean air
7. iron
8. milk
9. steel
10. Gatorade
11. blood
Pure Substance
E or C
Mixture
H or S
H