Name:
Hour:
Unit 1 Review
1.
What is the scientific method and how is it used to solve both scientific and everyday problems?
~ making an observation
~ Forming a hypothesis
~ Collecting Data
~ Drawing conclusions about data
2.
We use this technique to problems solve why things do not work.
Explain, on a microscopic level, how a solid differs from a liquid and how a liquid differs from a gas.
Solid
Liquid
Gas
Word Bank
Bonds
Chemical (2x)
Compound
Conservation of Mass
Element (2x)
Energy
Gas
Heterogenous
Homogenous
Liquids
Matter
Mass
Mixture
Physical (3x)
Plasma
Ratio
Scientific
Solid
Solution
Space
Complete the following paragraphs by using appropriate words, numbers or short phrases to give meaning to the
sentences.
Chemistry is a natural science that deals with MATTER (1) and the changes it undergoes. Matter is anything that has MASS
(2) and occupies SPACE (3) . Matter exists in four states SOLID (4), LIQUID (5), GAS (6) and PLASMA (7).
Chemists use the SCIENTIFIC (8) method to learn how matter can be changed and how ENERGY (9) is involved in these
changes. A physical combination of two or more substances is a MIXUTRE (10). A mixture has variable composition and
may be identified as HOMOGENOUS (11) or HETEROGENOUS (12). Homogeneous mixtures are known as SOLUTION (13)
and have both uniform composition and properties.
A pure substance is either a(n) ELEMENT (14) or a COMPOUND (15). Compounds are made up of ELEMENTS (16) which are
always present in the same RATIO (17) in a given compound. Compounds can only be separated into their constituent
elements by CHEMICAL (18) means only. A change in the properties of a substance without a change in the composition is
a CHEMICAL (19) change. If the composition changes, then a CHEMICAL (20) change has occurred. In a chemical reaction
BONDS (21) are broken and new bonds form. PHYSICAL (22) changes are usually reversible; many CHEMICAL (23) changes
are not easily reversible. The law of CONSERVATION OF MASS (24) states that mass is neither created or destroyed in any
physical or chemical reaction.
Sometimes, Always or Never True – Classify each of these statements as true (T), sometimes true (ST) or False (F)
F 22. Qualitative measurements give results in a definite form, usually as numbers.
ST 23. If the mass of an object is measured on the same balance by three different people and each determines that the mass
is 2.3 g the balance is very accurate.
F 24. Zeros at the end of a measurement and to the right of the decimal point are not significant.
T 25. Significant figures include all the digits that can be known accurately plus a last digit that must be estimated.
T 26. answer to calculations done with scientific measurements cannot be more precise than the least precise measurement.
F 27. The SI base unit of mass measurement is the milliliter
T 28. The density of a substance decreases as its temperature increases.
F 30. Density can have units of grams per centimeter squared
F 32. The SI unit for mass is the kilogram.
Density
1.
A rock has a mass of 127 grams and when placed in water displaces 32.1 mL of water. What is the density of the rock?
3.96 g/ml
2.
If the density of a solid is 4.2 grams/cm3 and you have 50. grams of the material what volume does it occupy?
12 cm3
3.
If you have 50. mL of a liquid that has a density of 0.92 g/mL , what is the mass of the liquid?
46 g
4.
If a block of plastic that is 5.0 cm x 6.5 cm x 3.0 cm has a density of 1.12 grams /cm3 what will the block weigh?
109 g
Short Answer
1.
Classify the following as a pure substance or mixture and if it is a mixture is it homogeneous or heterogeneous?
a.
Hand Cream
Homogenous
b.
Strawberry
Heterogonous
c.
Aluminum Foil
Pure Substance
d.
Mayonnaise
Homogenous
e.
Baking Soda
Pure Substance
f.
Elmer’s glue
Homogenous
g.
Milk
Homogenous
h.
Diamonds
Pure Substance
i.
Sugar
Pure Substance
j.
Peanut butter
Both Homogenous and Heterogonous depends on the type
2.
3.
5.
Identify the smallest particle in a(n)
a.
Element
Atom
b.
Compound
Element
Identify as a chemical of physical change:
4.
Define: Get from your textbook or notes
a.
Melting gold
Physical
a.
Quantitative observation
b.
Burning wood
Chemical
b.
Qualitative observation
c.
Frying an egg
Chemical
c.
Precision
d.
Dissolving salt in water
d.
Accuracy
e.
Copper roof turning green Chemical
e.
Chemical Change
f.
Breaking a window
Physical
f.
Physical Change
g.
Hydrogen gas exploding
Chemical
g.
Chemical Property
h.
Boiling water
Physical
h.
Physical Property
Physical
Complete the following table:
Volume
Shape
Space Between
Kinetic Energy
Particles
Solid
Fixed
Fixed
Close
Low
Liquid
Fixed
Variable
Medium
Medium
Gas
Variable
Variable
Far apart
high
6.
7.
8.
If you are converting kilograms to mg you are actually:
a.
Multiplying by 1000
d. Dividing by 10000
b.
Multiplying by 1,000,000
e. Dividing by 100,000
c.
Dividing by 1000
Round 398999999 to the appropriate number of significant digits.
a.
1 significant figure 4 x 108
b.
2 significant figures 4.0 x108
c.
3 significant figures 3.99 x108
d.
4 significant figures 3.999 x108
In the laboratory how would you mix water with acid?
Add acid to water
9.
How can you tell that a chemical reaction has stopped?
Bubbling as stop, the temperature is no longer increasing; color has stopped changing, no more formation of a
precipitate.
10. When reading laboratory instruments with incremental marks on them how do you read them to the correct number
of significant figures?
One more place past the last known digit.
11. How would you read the following volume of a graduated cylinder?
6.34 ml
12. Using the ruler provided measure the bold lines. Make sure you use significant digits
_________________________________________________ = 6.42 cm
_______________ = 1.90 cm
________________________________________ = 5.23 cm
13. Take the average of the three lines. Make sure you record the right number of sig figs.
13.55 cm
14. How many hours are in a half year?
4380 hours
15. If each student needs 4 grams of Copper to complete a lab and there is a bottle with 600 grams of copper in it, how
many students will get copper before you run out?
150 students will get copper
16. If chemistry class is 74 mins long how many seconds will you have been in chemistry by the end of the trimester? (13
weeks in a trimester) (65 days in a trimester)
288,600 sec or 2.9 x 105
****Reminder – Review your quiz because the material from the quiz will be on the test!!
Counting significant digits
Graphing
Scientific Notation
Metric conversion