updated chapter 1 Flashcards
what is a molecule
a molecule that consists of one or more atoms joined by a chemical bond
what does constant composition mean
the compound is made up of the same elements in the same proportion or ratio
what is an example of a constant composition?
h20, it has the same ratio of hydrogen to oxygen
what does pure substance mean?
something with a constant composition. It has the same properties regardless from where you extract it from.
Give an example for a pure substance and what it means
sucrose (sugar) contains the exact same amount of elements regardless of where you get your sugar from.
what do you call pure substances that cannot be broken down further?
an element
what are the two types of pure substances?
elements and compounds
if a pure substance can be broken down, what is it called?
a compound
compounds can be broken down into other __
elements
a mixture is composed of __ or more types of matter
two
a mixture with a composition that varies from point to point is called __?
heterogeneous mixture
why would something like chocolate cookies be considered a heterogeneous mixture?
heterogeneous mixtures are chocolate chip cookies(we can see the separate bits of chocolate, nuts, and cookie dough)
what is the definition of a homogenous mixture?
has a uniform/consistent composition
what do homogenous mixtures look like visually?
consistent
what is an example of a homogenous mixture? and why?
a sports drink because you get the same components of the sports drink on every sip
if a pure substance can be simplified chemically, what it is it?
a compound
if a pure substance CANNOT be simplified chemically, what it is it?
element
if a mixture has a uniform consistency, what is it?
a homogenous mixture
if a mixture DOESN’T have uniform consistency, what is it?
a heterogenous mixture
if matter has constant properties, what is it?
a pure substance
if matter DOES NOT have constant properties, what is it?
a mixture
is muddy water a pure element, a mixture, pure compound, a homogenous or heterogeneous mixture?
heterogeneous
is distilled water a pure element, a mixture, pure compound, a homogenous or heterogeneous mixture??
compound because it is pure h20
is sea water a pure element, a mixture, pure compound, a homogenous or heterogeneous mixture??
homogenous
is beer a pure element, a mixture, pure compound, a homogenous or heterogeneous mixture??
homogenous
is vitamin c a pure element, a mixture, pure compound, a homogenous or heterogeneous mixture??
compound
how does a homogenous mixture differ from a pure substance?
a mixture can have a variety or a lot of compositions; whereas a pure substance has a definite composition
how do molecules of elements and molecules of compounds differ? how are they similar?
different by: the molecules of elements contain one type of atom; molecules of atoms contain two or more types of atoms. Similar: they are similar because the ATOMS are chemically bounded
Classify each of the following as an element, a compound, or a mixture: a) iron b) oxygen c) mercury oxide d) pancake syrup e) carbon dioxide F) a substance with a hydrogen atom and a chlorine atom
Iron: element oxygen: element mercury oxide: compound pancake syrup: mixture carbon dioxide: compound f) compound
- Identify each as a heterogeneous mixture or a homogeneous mixture. a)Salt is mixed with pepper. b)Sugar is dissolved in water. c)Pasta is cooked in boiling water
a) hetero b) homo c) hetro
are two hydrogen elements combined together a compound? and why?
it is not a compound because you cannot have a compound with the same element
what is the difference between organic and inorganic compounds
organic compounds have a carbon atom and non organic do not have a carbon atom
explain the main differences between ionic and non ionic compounds?
ionic has a metal and non metal non ionic has two non metals
how are covalent bonds created?
created by a sharing of electrons between two atoms
compounds exist as either
molecules or crystals (ionic compounds)
homogeneous mixtures are often called?
solutions
if salt dissolves in water, this would be an example of a homogenous or heterogenous mixture?
homogenous
mixing sand and water would be an example of what kind of mixture?
heterogonoues
why would mixing gatorade with sand be a heterogenous mixture?
because sand would not mix/dissolve in gatorade
what are the two properties of matter?
physical properties and chemical properties
definition of physical properties?
describes the phyical characteristics of a substance
give 3 examples of a physical property?
colour, mass, shape
are thermal and electric conductivity examples of physical properties or chemical properties?
physical
definition of chemical properties?
properties shown when a substance interacts with substances OR changes into another substance
what are some examples of chemical properties
flammability, reactivity with oxygen
what are the two different types of properties
intensive and extensive properties
definition of a intensive properties? and what are two examples?
properties that do not depend on the amount of matter present. Temperature and density
define extensive properties, and give 3 examples.
properties that depend on the amount of matter present. Heat, mass, volume
intensive properties can also be defined as
independent amount of matter
what are the two different types of changes of matter?
pysical and chemical changes.
what is a physical change and what is an example?
a change that does not change the identity of a substance. EX: a phase change
what is a chemical change?
a change that results in a change of identity of a substance
a chemical change is also known as a
chemical reaction
a ice melting to liquid is an example of a chemical change or a physical change and why?
physical change because there are no changes being made to the identity of the substance
digestions of food is considered a
chemical change
when given a question about chemical/ physcial change, what is a good question to ask?
am I creating something new or is it just changing phase?
what is always associated with change?
energy
energy can be classified into two kinds of energy
kinetic energy and potential energy
what is associated with kinetic energy?
motion
what is associated with potential energy?
energy stored in a system
heat is the energy flow due to difference in ___
temperature
temperature is a measure of what
measure of the average kinetic energy of particles
what are the two types of reactions?
endothermic and exothermic reaction
endothermic process means what?
when a system absorbs heat it is endothermic
if a system releases heat, it is a __ process?
exothermic
if you break a bond, it is a what kind of process?
endothermic (requires energy)
a liquid to a gas is a endothermic or exothermic process?
endothermic
when a bond forms, what process is included?
exothermic
gas to liquid then liquid to gas is what?
vaporization in the former condensation in the latter
gas to solid and solid to gas
deposition sublimation
why during the phase changes (melting, freezing, etc..) is temperature constant?
have to overcome the intermolecular forces
explain why temperature does not increase during a transition from solid to liquid
because all of the energy is going into separating the intermolecular forces
what is the 5th phase of matter?
Bose-Einstein condensate
what is the laboratory technique used when keeping the liquid once it becomes steam called
distillation
what does the condenser do in a distillation device?
the condenser cools the heat which turns it back to liquid.
decantation means
pouring the liquid and let the solids remain
what is a very important tool for when doing chemical analysis
chromatography
what is chromatography used for
separating substances in complex mixtures
centrifugation does what
spins really fast, then separates substances
what is the fundamental difference between a compound and a mixture of elements
a compound has a chemical bond; a mixture of elements does not have a chemical bond and has weak intermolecular forces
Why is it more difficult to separate elements in a compound from each other than to separate elements in a mixture or compounds in a mixture?
to break a chemical bond it requires a lot of energy/heat a mixture of elements require little energy/heat since it has a low intermolecular force
What determines the melting and boiling points of substances?
it depends on the level of the intermolecular force
Why don’t all chemical substances react together all the time? Why is it that some substances can be together and not react?
Chemical reactions don’t all occur at the same rate. … If you want a chemical reaction to happen faster, the particles of the reactants need to collide either more quickly or with more energy.
how do you determine how many significant figures are there?
every non zero in a number
how many significant figures are in 234
3
when a zero is in between two real numbers, how many significant numbers are there?
3
7094 has how many significant numbers?
4
how many significant figures in 5006?
4
what is the difference of significant numbers between 500 and 500.?
500: trailing zeros has one 1 500. : has 3
in 0.00836, how many significant numbers?
3
Assuming that the measurement 0.006580 kg is properly reported, the three leading zeros are not significant.. A. True B. False
True
In the number 0.0059830, what is its name, and is it significant?
Trailing zero; yes it is counted as significant
knowledge that comes from sensory experiences is called
empiricism
liquid to gas is called
evaporation
gas to liquid is called
condensation
