Chemistry
Study Guide: Test #1
A hypothesis is best
described as:
An educated guess
If …….then……..
The scientific method is:
A systematic approach to
answer a question - testable
A scientific theory is best
described as:
An explanation supported
by many experiments
The dependent variable is
best described as:
The one that changes;
located on the Y axis
In an experiment, the
independent variable is
the one that:
“I” can control; located on
the X axis
The best way to find the
volume of a marker is called:
Water displacement
The formula for density is:
D = m/v
In determining how many significant
figures a number has, you must first
look for a
decimal
If a decimal is present, then you start counting
from the front (left)
If a decimal is absent, then you start counting
from the back (right)
Pacific
Atlantic
The first rule of lab safety
is:
Tell the teacher
Volume is measured in mL or
cm3, which are the same
Density is written in which
units? g/mL or g/cm3
When measuring
irregular objects
(such as cylinders,
marbles, rocks) you
should use water
displacement as the
method of finding
volume.
You can only use the
L*W*H method of
finding volume when
objects are
considered regular in
shape or easily
measured with a ruler.
Metric Measurements
Kilo
1000
Hecto
100
Deca
10
m
L
g
deci
centi
milli
10
100
1000
Kids have dropped over dead converting metric
Which prefix means
1,000?
Kilo
Which prefix means
1/100? centi
Which prefix means
1/1000?
milli
Read the following graduated cylinders. Make
sure to include (mL) in your answer
52.9 mL
6.64 mL
20.6 mL
Descriptor
Qualitative or Quantitative
Red
Qualitative
17 centimeters
Quantitative
46 desks
Quantitative
Rusty
Qualitative
48 marbles
Quantitative
152 milliliters
Quantitative
Smelly
Qualitative
Calculate the densities of the following objects. Remember to
place units after each number.
Object A:
Object B:
Length = 6 cm
Width = 3 cm
Height = 1 cm
Mass = 36 g
Length = 10 cm
Width = 5 cm
Height = 2 cm
Mass = 300 g
Volume = 18 cm3
Density = 2 g/cm3
Volume = 100 cm3
Density = 3 g/cm3
Object C:
Use the water displacement
method to determine the
density of Object C (silly
putty)
Initial water level in
graduated cylinder =
25 mL
Water level after placing
silly putty into graduated
cylinder = 29 mL
Mass of silly putty = 8g
Volume = 4 mL
Density = 2 /mL
Which of the following materials will float on water
(density = 1.00 g/cm3)?
Corn oil = .93 g/cm3 -- float
Glycerine = 1.26 g/cm3 -- sink
Corn syrup = 1.38 g/cm3 -- sink
Wood = .85 g/cm3 -- float
Steel = 7.81 g/cm3 -- sink
Rubber = 1.34 g/cm3 -- sink
Ice = .92 g/cm3 -- float
Water = 1.00 g/cm3 -- neither
Round the following to 3 significant figures
124.78
1.001
56.0
78.490
175.689
125
1.00
56.0
78.5
176
Complete the following calculations
be sure to use the proper number of significant figures
51.8 kg + 65.23 kg = 117 Kg
1 m3
16 m x 31 m x 0.003 m = 1.488
3.45 m ∕ 2.1 s = 1.6 m/s
45.21 x 3.0 = 136.63
12.01 g - 6.0 g = 6.01
140____
6.0 g
Describe each of the following as:
accurate – precise – both - none
None
BOTH
Precise
None