Chemistry Unit 1 Test Flashcards
measures how correct or close to the truth a measurement is
accuracy
measures how specific or consistent a measurement is
precision
standard unit for length
Meter (m)
standard unit for mass
Kilogram (kg)
standard unit for time
Seconds (s)
standard unit for temperature
Kelvin (K)
standard unit for amount of substance
Mole (mol)
example of scientific investigation design with appropriate constants and variables (IV and DV)
a. Drinking coffee leads to being more productive.
IV=
DV=
Control Group=
Experimental Group=
Constants=
whether or not you drink coffee
how much work I can get done in a certain amount of time
not drinking coffee
drinking coffee
same type of work/task, same food, same amount of sleep beforehand, same environment to work in
a substance that exists in a solid state has:
a. definite shape
b. definite volume
c. particles that only vibrate
all of the above
the variable that is changed during an experiment is called what type of variable?
manipulated
what is the formula for % error?
%error= |experimental value - accepted value/accepted value| x100
Is mass an intensive or extensive property?
extensive
The simplest form of matter with unique properties is/are…
element
when the temperature of a substance increases, what happens to its density?
the density decreases
a cylindrical container with a flat bottom
beaker
conical flasks with wide flat bottoms and tapered necks
erlenmeyer flask
which is NOT an example of applied chemistry?
studying compounds containing nitrogen
a clear glass or plastic container that is much longer than it is wide, commonly has a U-shaped bottom, and has an open top
test tube
a slender tube attached to or incorporating a bulb, for transferring or measuring out small quantities of liquid, especially in a laboratory
pipette
a tall narrow container with a volume scale used especially for measuring liquids
graduated cylinder
a kind of ambient air gas burner used as laboratory equipment; it produces a single open gas flame
bunsen burner
What are the 4 rules for sig figs?
a. All non-zero numbers are significant
b. All zeros that are between non-zero numbers are significant.
c. Leading zeros are non-significant.
d. Trailing zeros for a whole number when a decimal is present are significant.
How many significant figures are in:
3.01
850
7
102.0
0.00990
3
2
1
4
3
objective; based on senses
observation
subjective; based on perceptions
inference`
data based on qualities
qualitative data
data based on quantities (numbers and measurements)
quantitative data
ratios of equivalent values (meaning they equal 1)
conversion factors
the number of digits in a measurement that reflect how accurate the measurement is
significant figures
give an example of a conversion factor
explain what it means, how it can be used, and at least two different ways it can be written
A conversion factor is a number used to change one set of units to another, by multiplying or dividing. When a conversion is necessary, the appropriate conversion factor to an equal value must be used. For example, to convert inches to feet, the appropriate conversion value is 12 inches equals 1 foot.
Explain the significance of scientific notation and why it is important to be able to use it.
Scientific notation is a technique used to rewrite large or very small numbers into a format that is easier to use.
PRACTICE QUESTIONS:
1. Convert the following values -
a. 21 days into seconds =
b. 9,602 grams into pounds =
c. 5,500 millimeters into yards =
a. 1,800,000 s
b. 21.16 lbs.
c. 6.1 yds
PRACTICE QUESTIONS:
2. Write the following values in scientific notation -
a. 801,000 - 3 sig figs =
b. 2,950,000 - 3 sig figs =
c. 0.0518 - 3 sig figs =
d. 0.00000006 =- 2 sig figs =
a. 8.01 x 10^5
b. 2.95 x 10^6
c. 5.18 x 10^-2
d. 1.6 x 10^8
a technique for converting numbers into different units, without changing their value
dimensional analysis
To be an element or compound, it must be a …
pure substance
Iron Metal or Fe is an example of …
an element
Table Salt or NaCI is an example of…
a compound
To be homogeneous or heterogeneous it must be a…
mixture
Is apple juice an element, compound, homogeneous mixture, or heterogeneous mixture?
homogeneous mixture
Is salad dressing an element, compound, homogeneous mixture, or heterogeneous mixture?
heterogeneous mixture
Does melting involve a change in chemical properties?
no
the gas state of a substance that normally exists as a solid or liquid at room temperature is
vapor
Is boiling water an irreversible physical change?
no
if every person in your group gets the same answer but it is not close to the accepted value, what can you say about your group?
“we are precise”
if i was given the temperature 400 Kelvins and I wanted to change it to Celsius, what would I end up with?
127 degrees Celsius
a well-tested explanation for a broad set of observations
theory
when an iron nail is grounded into does its mass change?
no
Is this formula correct? m=d/v
no
what are the 5 traditional areas of study of chemistry?
Organic chemistry, biochemistry, inorganic chemistry, analytical chemistry, and physical chemistry
What is the difference between a compound and a mixture?
Compounds are substances which can be formed by chemically combining two or more elements. Mixtures are substances that are formed by physically mixing two or more substances.
anything that has mass and volume
matter
a measure of the amount of matter
mass
a measure of how much space something takes up
volume
the smallest unit of an element that maintains the identity of the element
atom
a pure substance that cannot be broken down into anything simpler or more stable
element
a pure substance that can be broken down into simple and more stable substances (elements)
compound
a type of matter that has a definite composition and can be identified by its unique set of properties
substance
a physical blend of two or more components
mixture
a mixture in which the composition is uniform throughout
homogeneous mixture
a mixture in which the composition is not uniform throughout
heterogeneous mixture
another name for a homogeneous mixture
solution
a solution in which the solvent is water
aqueous solution
solution of metals
alloy
states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as the system’s mass cannot change, so the quantity can neither be added nor be removed
law of conservation of matter
PRACTICE QUESTION: A piece of plastic with a mass of 15g is placed in a graduated cylinder. The water rises from 32mL to 52mL when the plastic is added. Find the density of the plastic.
P = m / vF - vI
P = 15g / 52mL - 32mL
P = 750 kg/m^3
a ________ ______ is a process in which substances are changed into different substances.
chemical change
a method for separating a solid from in a heterogeneous mixture is called
filtration
elements combine chemically to form
compounds
an experiment is means for testing a
hypothesis
pepperoni pizza is a _______ and it is a(n) _____________ _______.
mixture, heterogeneous mixture
carbon is a _________ and it is a(n) _______.
substance, element
tap water is a _______ and it is a(n) ___________ _____
mixture, homogeneous mixture
carbon dioxide is a _________ and it is a(n) ________.
substance, compound
what are 2 possible indicators (out of 4 that we discussed) that would show a chemical change, a change in composition, had occurred
color change, bubble fizzes
2 different samples of copper have the same intensive properties. how could they have different extensive properties?
they could have different volumes
list some signs that may demonstrate that a chemical reaction has occurred
Various signs of a chemical reaction include:
Change in Color.
Formation of a Gas.
Formation of a Precipitate.
Change in Odor.
Change in Temperature.
Something is Burning.
Light is Being Produced.
What is the difference between a physical and chemical change?
Physical changes are those in which the shape, size, or state of the matter changes, but the substance is still essentially the same. For example, chopping up a carrot or ice melting into water are both physical changes. Chemical changes are those where one or more substances are combined to produce a new substance.
What results in a chemical reaction occurring?
A chemical change occurs when the composition of a substance is changed, which requires the breaking and forming of chemical bonds during a chemical reaction.
