Which of the following is/are heterogeneous mixtures?
Gasoline
Tea
Italian salad dressing
White wine
Vinegar
Beach sand
Dirt
Which of the following is/are heterogeneous mixtures?
Italian salad dressing, Beach sand, Dirt
The rest are solutions.
Which of the following processes do not represent
chemical changes?
Iron rusting
Distillation of a liquid
Reaction of sodium metal with water
Leaves changing color
Dissolving sugar in water
Filtration of a solid from a liquid
Which of the following processes do not represent
chemical changes?
Distillation of a liquid, Dissolving sugar in water,
Filtration of a solid from a liquid are physical changes.
Iron rusting, Reaction of sodium metal with water,
Leaves changing color are chemical changes.
Which of the following do not represent physical
properties?
Boiling point
Color
Reaction with oxygen
Conductivity of gold
Burning of gasoline
Which of the following do not represent physical
properties?
Reaction with oxygen , Burning of gasoline are
chemical properties
Boiling point, Color, Conductivity of gold are physical
properties
Which of the following is/are compounds?
Distilled water
Iron
Milk
Air
Table salt
Aspirin tablets
Which of the following is/are compounds?
Distilled water, Table salt are compounds
Iron is an element
Milk, Air, Aspirin tablets are mixtures
How many g are there in 0.0134g?
How many g are there in 0.0134g?
1g = 106 g
0.0134g x (1x106 g/1g) = 13,400g
Or 1.34x104 g
Which metric prefix would
replace the power of ten in
3.68x10-3m?
Which metric prefix would
replace the power of ten in
3.68x10-3m?
10-3 is refers to milli, so the
number would be
3.68millimeters.
Can a set of measurements be precise without being
accurate? Can the average of a set of measurements
be accurate even if the individual measurements are
imprecise?
Can a set of measurements be precise without being
accurate? Can the average of a set of measurements
be accurate even if the individual measurements are
imprecise?
Yes, data measurements may be close to one another
(precise) but not be close to the accepted value. This
type of error usually occurs from a miscalibrated
instrument.
Yes, if the average of the imprecise measurements
happens to be close to the accepted, published value.
This is not an acceptable way of data collection
however.
Use exponential notation to
express each of the following
measurements in terms of SI
base units.
1.09ng
90.1ms
145pm
Use exponential notation to express each of
the following measurements in terms of SI
base units.
1.09ng x (1kg/1x1012ng) = 1.09x10-12kg
90.1ms x (1s/1x103ms) = 9.01x10-2s
145pm x (1m/1x1012pm) = 1.45x10-10m
Ray Bradbury chose
“Fahrenheit 451” as the title
of his novel about book
burning in a future society. A
firefighter told him that is the
temperature at which paper
ignites. What would his title
have been had be been given
the temperature in degrees
Celsius?
Ray Bradbury chose “Fahrenheit 451” as the title of
his novel about book burning in a future society. A
firefighter told him that is the temperature at
which paper ignites. What would his title have
been had be been given the temperature in
degrees Celsius?
oC = (5/9)(451oF – 32)
= 233oC
The highest temperature
ever recorded in Phoenix,
Arizona was 50.0oC. Express
this in oF?
The highest temperature
ever recorded in Phoenix,
Arizona was 50.0oC. Express
this in oF?
oF = (9/5) 50.0oC + 32
= 122oF
Determine the number of L in
a box that measures 4cm x
8cm x 10cm.
Determine the number of L in a box that
measures 4cm x 8cm x 10cm.
= 4cm x 8cm x 10cm = 320cm3 (raw data)
= 3x102cm3 based on round-off rules.
3x102mL x (1L/1,000mL) = .3L = 3x10-1L
Determine the number of
significant digits in the
following numbers:
2.3000x106
45.1
800000.103
.000000001500
600
500.
Determine the number of significant digits in the
following numbers:
2.3000x106
(5)
45.1
(3)
800000.103
(9)
.000000001500
(4)
600
(1)
500.
(3)
A bathroom-type scale is
calibrated (marked off) in
tenths of a kilogram from 1 to
200kg. Determine how many
significant figures should be
used to express the mass of
anyone using the scale
whose mass is between 10
and 99kg.
A bathroom-type scale is calibrated (marked off) in
tenths of a kilogram from 1 to 200kg. Determine how
many significant figures should be used to express
the mass of anyone using the scale whose mass is
between 10 and 99kg.
4 digits are allowed. If the scale is calibrated in
tenths, then it is the 100ths place that is uncertain.
Based on the allowed digit of uncertainty, this gives a
total of four. For example 25.46kg
How many significant figures
does the result of the
following operation contain?
8.5201 + 1.93
How many significant figures does the result
of the following operation contain?
8.5201 + 1.93
This is addition, and therefore depends on the
least number of digits after the decimal point.
Since 1.93 only has two, the “raw” result from
the calculator (10.4501) is reported as 10.45.
If a car has an EPA mileage
rating of 30 miles per gallon,
what is this rating in km/L?
If a car has an EPA mileage rating of 30 miles
per gallon, what is this rating in km/L?
30mi/gal (1.609km/1mi)(1gal/4qt)(1.057qt/1L)
12.755 = 13km/L
An aluminum beverage can
contains 12 fluid ounces.
Express this volume in
microliters, given 1 fl. oz. =
29.6mL
An aluminum beverage can contains 12 fluid
ounces. Express this volume in microliters, given
1 fl. oz. = 29.6mL
12oz. (29.6mL/1oz.)(103L/1mL) = 3.6x105L
Magnesium (Mg) and iron (Fe)
have densities of 1.7g/cm3
and 7.9g/cm3 respectively. If
a sample of iron has a mass
of 826g, what is the mass of a
block of magnesium that has
the same volume as the block
of iron?
Magnesium (Mg) and iron (Fe) have densities of
1.7g/cm3 and 7.9g/cm3 respectively. If a sample of
iron has a mass of 826g, what is the mass of a block
of magnesium that has the same volume as the block
of iron?
The mass of Mg needed is
826g * (1.7g/cm3 / 7.9g/cm3)
= 177.75 = 1.8x102g
An irregularly shaped piece
of metal with a mass of 125g
is placed into a graduated
cylinder that contains
25.00mL of water. This raises
the water level to 56.00mL.
What is the density of the
metal?
An irregularly shaped piece of metal with a mass of
125g is placed into a graduated cylinder that
contains 25.00mL of water. This raises the water
level to 56.00mL. What is the density of the metal?
125g / (56.00mL – 25.00mL) = 4.03g/mL
A student performs a density
experiment and achieves the
following results:
2.33g/mL
2.32g/mL
2.31g/mL
The published value for the
density of the object is
2.65g/mL. Comment on the
accuracy and precision of
the experiment.
A student performs a density experiment and
achieves the following results:
2.33g/mL
2.32g/mL
2.31g/mL
The published value for the density of the object is
2.65g/mL. Comment on the accuracy and precision
of the experiment.
The data results are reasonably precise, but not very
accurate.
Perform the following conversions to the correct
number of significant digits:
642g
2.65m3
68.4in
94ft
1.2lb
248lb
1.85gal
=
=
=
=
=
=
=
_____kg
_____cm3
_____cm
_____m
_____g
_____kg
_____L
Perform the following conversions to the correct
number of significant digits:
642g(1kg/1,000g)
2.65m3(106cm3/1m3)
68.4in(2.54cm/1in)
94ft(1m/3.281ft)
1.2lb(453.6g/1lb)
248lb(.4536kg/1lb)
1.85gal(1L/.2643gal)
=
=
=
=
=
=
=
.642kg
2.65x106cm3
174cm
29m
5.4x102g
112kg
7.00L
A fertilizer contains 21% nitrogen by mass. What
mass of this fertilizer, in kilograms, is required for
an application of 775g of nitrogen?
A fertilizer contains 21% nitrogen by mass. What
mass of this fertilizer, in kilograms, is required for
an application of 775g of nitrogen?
775g = .775kg
.775kg = .21x
x = 3.7kg of nitrogen (to the correct number of
significant digits)
Calculate the mass of a block of iron (density =
7.86g/cm3) with dimensions of 52.8cm x 6.74cm x
3.73cm.
Calculate the mass of a block of iron (density =
7.86g/cm3) with dimensions of 52.8cm x 6.74cm x
3.73cm.
D = m/V
m = DV
(7.86g/cm3)(52.8cm x 6.74cm x 3.73cm)
= 1.04x104g
Perform the following calculations; express each
number and the answer in exponential form with
the appropriate number of significant figures.
a.
320x 24.9
0.080
b. 432.7 x6.5 x0.002300
c. 32.44  4.9  0.304 d.
82.94
62 x0.103
8.002  0.3040
13.4  0.066  1.02
Perform the following calculations; express each
number and the answer in exponential form with
the appropriate number of significant figures.
a. 99,600 = 1.0x105
c. .4461… = 4.46x10-1
b. 1.01297… = 1.0x100
d. .5768… = 5.77x10-1
You decide to establish a new temperature scale
on which the melting point of mercury (-38.9oC) is
0oM and the boiling point of mercury (356.9oC) is
100oM. What would be the boiling point of water in
degrees M? The temperature of absolute zero in
degrees M?
You decide to establish a new temperature scale
on which the melting point of mercury (-38.9oC) is
0oM and the boiling point of mercury (356.9oC) is
100oM. What would be the boiling point of water in
degrees M? The temperature of absolute zero in
degrees M?
The ratio of the two temperature scales are
(356.9oC- -38.9oC)/(100oM-0oM) 1oM=3.958oC
In addition, the zero point on the M scale = -38.9oC.
Therefore, oC = 3.958oM -38.9
BP H2O = 100oC = 35.1oM
Ab. Zero = -273.15oC = -59.2oM
The volume of a red blood cell is about 9.00x10-11cm3.
Assuming that red blood cells are spherical, what is
the diameter of a red blood cell in inches?
The volume of a red blood cell is about 9.00x10-11cm3.
Assuming that red blood cells are spherical, what is
the diameter of a red blood cell in inches?
V = 4/3 r3 for a sphere
Diameter = 2r
r = (3V/4)1/3
= 2.78x10-4cm
Diameter = 2.78x10-4 x 2 = 5.56x10-4cm
5.56x10-4cm x (1in/2.54cm) = 2.19x10-4in