Chem Semester 1 Review
A compound has 15.39 g of gold for every 2.77 g of chlorine. Simplified, there is ____ g of gold for every 1 g of chlorine. (Round to two decimal places)
5.56
Why do nutrients need to be added to the soil?
Different areas have different concentrations of nutrients. Crops also deplete certain nutrients each year.
How is most scientific research carried out today?
Mostly at private companies or Universities.
Which compound has the lowest ratio of nitrogen to oxygen?
N2O5
How was the nitroglycerin made more stable?
Nitroglycerin was mixed with Silica to stabilize it and form a solid material
Who owned the gold mines during ancient Egyptian and Roman Civilizations?
No specific group or individual, they were a property of the state
Is it always easy to classify research as pure or applied? Explain your answer.
No, sometimes it could start off as pure then end up as applied (line isn't always distinct)
Salt is a pure compound. (T/F)
True
The melting point, boiling point, and freezing point of a substance can be determined easily and exactly and are known as the physical properties. (T/F)
True
Stan is researching a new insecticide that will be less toxic to birds and mammals that may come in contact with it.
applied chemistry
What was the basic shortcoming of the Greek philosophers approach to studying the material world?
asking questions, discussing/debating them
John Dalton
atomic theory, atoms can combine to form compounds
Democritus believed that all natural substances were made of _____.
atoms
What is all matter made of?
atoms
According to the atomists, the entire physical world was made of:
atoms and void
In carbonated water, when carbon dioxide bubbles are thoroughly mixed into the water, they become invisible. What type of mixture is carbonated water?
solution
acceleration (a)
speed/time (m/s^2)
Law
statement that is always true without explanation
Substances can exist in three _____ / _____
states, phases
potential energy
stored energy
Elixir of Life
substance believed to give immortality to the person who possessed it
Lemonade is a murky yellow color. If you leave it sitting for a few minutes, you might need to stir it again before you drink it. What type of mixture is lemonade?
suspension
Define "deductive reasoning"
taking the general principle and drawing a specific conclusion
chemical property
the ability of a substance to undergo a specific chemical change
energy
the ability to do work
analytical chemistry
the area of study that focuses on the composition of matter (measuring mercury in seawater)
What two things need to be studied to develop a new drug?
the chemistry of the disease and how the drug may affect the body
precision
the exactness of a measurement
How do hand warmers work?
the iron fillings inside the package react with the air to release thermal energy
In a distillation process, which liquid component of the mixture passes through the condenser first?
the one with the lower boiling point
chemical reaction
the process by which one or more substances change to produce one or more different substances
chromatography
the separation of a mixture by passing it in solution or suspension or as a vapor through a medium in which the components move at different rates.
organic chemistry
the study of carbon compounds (synthesizing new carbon compounds)
biochemistry
the study of substances and processes occurring in living things (studying enzymes in cells)
physical chemistry
the study of the properties and changes of matter and their relation to energy (making new compounds) (measuring the electrical properties of solutions)
Macroscopic world
the things we can see, touch, and measure directly
How do batteries create energy?
there is a release of electrons that flows through the circuit providing a current of electricity
Is it easy to classify research as pure or applied?
there is not always a clear line between the two (question can fall under pure research and lead to advancement of knowledge)
What did Erwin Schrodinger and Werner Heisenberg contribute to the atomic theory?
they created the quantum model and found that it is impossible to know the exact speech and location of electrons giving the model a cloud shape
pure research
to gain knowledge for the sake of knowledge itself
Air has its components spread evenly, so it is considered a homogenous mixture. (T/F)
true
Because the length, width and height of a cube are both extensive properties, the volume of the cube is also an extensive property. (T/F)
true
Compounds have fixed compositions whereas mixtures vary in composition. (T/F)
true
Properties of matter such as density, odor, color, and melting point do not vary with the amount of matter. Such properties are called intensive properties. (T/F)
true
T or F Every molecule of carbon dioxide consists of 1 atom(s) of carbon and 2 atom(s) of oxygen.
true
T or F The law of definite proportions is only applicable when the elements which are reacting together form the same product.
true
T or F According to Democritus, changes occur if atoms in an object are recombined or reconnected in different ways.
true
T or F Ancient Greek philosophers had many ideas about the natural world and how it worked.
true
T or F Atoms, according to Democritus, always existed and are unchangeable and indestructible.
true
T or F Democritus believed that atoms were always in motion.
true
T or F Democritus proposed the theory of atomism.
true
T or F Democritus stated that different atoms differ in magnitude.
true
T or F Democritus suggested that the complete universe is made up of minute particles which are indivisible.
true
T or F Protons have much more mass than electrons do.
true
T or F The ancient Greek philosophers spend their time by debate and discussion.
true
T or F The idea of the atom was the major contribution of Democritus made to the thinking of his day
true
T or F Whenever the same two elements form more than one compound, the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers.
true
The composition of a mixture is varied by altering the proportions of its constituents. (T/F)
true
Water is a homogeneous mixture which contains dissolved gases and minerals. (T/F)
true
evaporation
used to separate homogeneous mixtures when there is more than one dissolved solids
Give an example of applied research.
vaccination development for a virus
heterogeneous mixture
varies in composition throughout the mixture (rocks)
Which property of a glass of water is an example of an extensive physical property?
volume of water
Examples of extensive property are ____ and ____
volume, mass
Three things crops need for good growth
water, nutrients from soil and protection from insects
melting/boiling point
way to identify a compound
Which property of a glass of juice is an example of an extensive physical property?
weight
How does burning gasoline power a car?
when petroleum products are ignite, it creates a increase in gas and volume which provides power by moving pistons in the internal combustion engine
power = ________ / ________
work/time
Two ways chemists helped with issues related to lead contamination
developed methods to remove lead from the body, create new gasoline products with good fuel efficiency
Why nutrients need to be added to soil?
different areas have different levels of soil, crops also get rid of certain nutrients each year
JJ Thompson
discovered electrons, plum pudding model
Ernest Rutherford
discovered the positive nucleus, atom is mostly made of empty space, planetary model
In which of the following ways would one separate a miscible solution of benzene and chloroform?
distillation
What separation technique separates liquids using differences in their boiling points?
distillation
Which of the following is a viable method of separating gasoline from crude oil?
distillation
example of pure research:
early philosophers debated and discussed theories without practical application
Solar cells convert chemical energy to ______ energy
electrical
Where are liquid crystals used?
electronic displays (watches, calculators)
Heisenberg and Schrodinger
electrons are in orbitals, don't know where the electrons are located exactly (can't know their exact location)
Niels Bohr
electrons orbit the nucleus based on energy levels
Substances may either be _____ or ________
elements, compounds
Besides matter, all chemical reactions require _______ in order for the reaction to occur.
energy
exothermic reaction
energy is released when bonds form in products then is used to break bonds in reactants
endothermic reaction
energy is used to break bonds in reactants then is released when bonds form in products
kinectic energy
energy of motion (KE = 1/2mv^2)
For any chemical process in an isolated system in which all reactants are converted to products, the original mass of reactants must be _____ the final mass of products.
equal to
In _______, solids can be separated from liquids by heating the liquid and removing it.
evaporation
What separation technique is used to separate a dissolved solid from the liquid in which it is dissolved?
evaporation
A property that depends on the amount of matter (mass or volume) in a sample is an ______ property
extensive
A homogeneous mixture is a composition of two or more impure substances in a definite proportion, displaying non-uniform characteristics. (T/F)
false
A solution of salt and water is a heterogeneous mixture. (T/F)
false
Because mass and volume are both extensive properties, density (mass/volume) is also an extensive property. (T/F)
false
Because the amount (n) and the mass (m) of a substance are both extensive properties, the molar mass (molar mass = m/n) of the substance is also an extensive property. (T/F)
false
Because the amount of solute and the volume of solution are both extensive properties, concentration of a solution (amount of solute/volume) is also an extensive property. (T/F)
false
Because the more water you boil the more time it will take (other conditions are constant) the boiling point of water is an extensive physical property. (T/F)
false
Boiling point is not an intensive physical property. (T/F)
false
Chemical properties of matter are categorized as either intensive or extensive. (T/F)
false
Gases form heterogeneous mixtures with each other regardless of the identities or relative properties of the component gases. (T/F)
false
Mixtures are considered to be pure substances. (T/F)
false
Mixtures can only be separated by a chemical change. (T/F)
false
Solutions are heterogeneous since the ratio of solute to solvent does not remain the same throughout the solution. (T/F)
false
T or F A chemical compound is always found to be made up of the same elements combined together in different proportions by mass.
false
T or F According to Democritus, atoms are solid particles which are destructible.
false
T or F The neutron has a charge.
false
T or F An extension of Democritus theory states that there were different varieties of atomos with same shapes, sizes and masses.
false
T or F Atoms are the smallest particles in the universe.
false
T or F Greek philosophers accepted most of the discoveries on the basis of experiments they performed.
false
T or F In carbon dioxide, 12 grams of carbon combines with 16 grams of oxygen.
false
T or F Science and experimentation were active pursuits in ancient Greece.
false
T or F The theory of Democritus and Leucippus held that everything is composed of 'atoms', which are geometrically indivisible.
false
While carrying out filtration of a solution, the substance which remains on the filter paper is the water-soluble part. (T/F)
false
Separation by physical size is ______.
filteration
Democratis
first to discover the atom (found that it was uncuttable and that it was the smallest form)
What is not a physical property of matter?
flammability, reactivity with oxygen, ability to react chemically
work = _________ * __________
force * distance
energy (E)
force * length (J)
What did Democritus contribute to the atomic theory?
found matter can be cut into smaller pieces known as atoms (uncuttable)
Where was lead found in products?
gas, paint, plumbing pipes
Define "inductive reasoning"
getting a collection of specific examples and drawing a general conclusion
What chemical are diabetics unable to produce?
glucose
homogeneous mixture
has the same composition throughout the mixture (salt water), uniform composition
What did Niels Bohr contribute to the atomic theory?
he created Bohr's Model and found the atom is smaller than we thought with electrons in distinct orbitals around the nucleus
What did JJ Thomson contribute to the atomic theory?
he created the plum pudding model and discovered electrons
What did Ernest Rutherford contribute to the atomic theory?
he discovered most of an atom is empty space and all atoms have a positively charged nucleus in the center
A _______ mixture is a mixture in which the composition is uniform throughout the mixture.
homogeneous
Sugar dissolves completely in water to form a solution. This solution is a _____.
homogeneous mixture
law
how
accuracy
how close a measurement is to the true value
What are synthetic polymers made from?
hydrocarbons in petroleum products
Theory
hypothesis or guess confirmed repeatedly (offers description as to why something happened)
According to Aristotle, how long could one divide a grain of sand?
indefinitely
mass is _______ of location
independent
What word does the ancient greek word "atomos" roughly translate to?
indivisible
Louis is investigating a new way to isolate nickel from various nickel-containing rocks and sediment. Identify the type of chemistry.
inorganic
(identify type of chemistry) making new compounds for energy processes
inorganic chemistry
A property of matter that depends only on the type of matter in a sample and not on the amount is _____
intensive
Density is an _____ property
intensive
Melting point is an _____ physical property.
intensive
How do pesticides work?
interfere with the biochemical process of the pest
__________ is the SI base unit of energy
joule (J)
What is temperature's SI base unit?
kelvin (K)
What is mass's SI base unit?
kilogram (kg)
What law states that elements can combine with one another in different mass ratios?
law of multiple proportions
Which property of a strip of copper wire is an example of an extensive physical property?
length of strip
volume (V)
length x width x height (m^3)
speed, velocity (V)
length/time (m/s)
force = ________ * ________
mass * acceleration
acceleration = ______ /_______
mass / second ^2
force (F)
mass x acceleration (N)
density
mass/volume
density (D)
mass/volume (kg/m^3)
Superconductor
material able to conduct electricity with 100% efficiency
substance
matter that has a uniform and definite composition
inorganic chemistry
measuring the electrical properties of solutions (making new compounds for energy purposes)
What is length's SI base unit?
meter (m)
The two worlds of the chemist are the macroscopic and ________ world.
microscopic
Aspirin pills contain aspirin and some ingredients that don't have medicinal function, such as corn starch and cellulose. Based on this, would you classify an aspirin pill as a mixture or a pure substance?
mixture
What is the amount of substance SI base unit?
mole (mol)
What best describes gas particles?
moving randomly, colliding with each other, high kinetic energy
The radius of an atom is closest in size to a _________ .
nanometer
Will the composition of water vary depending on its source? (Yes or No)
no
liquid
no definite shape, definite volume, particles move freely
gas
no definite shape, no definite volume, particles move freely and are not attracted to each other
Give two examples of discoveries chemists have found to help surgical patients
non-reactive blood vessels used during heart and other surgeries, dissolvable materials that don't need to be removed
What do all atoms of the same element have in common?
number of protons
(identify type of chemistry) synthesizing new carbon compounds
organic chemistry
example of applied research:
petroleum companies finding better ways to power vehicles, create better lubricants to prevent engine wear and lower pollution
When oil and water are mixed, two separate layers form. Each layer is called a(n) _____.
phase
Color and shape are both examples of _____ properties
physical
(identify type of chemistry) measuring electrical properties of solutions
physical chemistry
A characteristic of a substance that can be observed or measured without changing the identity of the substance
physical property
product
present at the end of the chemical reaction, what is produced because of the reaction
reactant
present at the start of the chemical reaction
Who owned the gold mines during the ancient Egyptian and Roman civilizations?
property of the state not an individual person
A neutral atom has equal numbers of ______and electrons.
protons
_____ are attracted to negatively charged particles and repelled from positively charged particles.
protons
What is contained in the nucleus of an atom?
protons and neutrons
Tina is researching the rates of reactions of various compounds to see how the reaction rate depends on the solubility of the compound.
pure chemistry
applied research
research done to solve a specific problem or make advancements
How is research usually funded?
research groups raise money and government groups provide money
How do scientists share their findings?
scientific journals
What is time's SI base unit?
second (s)
chemical formula
shows the elements in the compound and the ratio of atoms
Nitroglycerin can be made more stable by mixing with ______.
silica
The color of most metals is ______.
silver
element
simplest form of matter that has a unique set of properties, can't be broken down
How does the mass of the neutron compare to the mass of the proton?
slightly greater
Microscopic world
small particles that make up all matter
Give two examples of chemistry in your everyday life
soap and cooking
states of matter
solid, liquid, gas
How much of the water used in farming is provided by irrigation?
18%
How much of water used in farming is provided by irrigation?
18%
In carbon dioxide, there is always 2.66 g of oxygen for every 1 g of carbon. How many grams of oxygen are in a 25.62 gram sample of carbon dioxide?
18.62
How many grams of carbon would be present in carbon monoxide that contains 2.66 grams of oxygen?
2
How many valence electrons does beryllium have?
2
compounds
2 or more elements chemically combined
synthesis reaction
2 or more reactants combine to synthesize a single product
In one compound of lead and sulfur, there are 6.46 g of lead for every gram of sulfur. In another, there are 3.23 g of lead for every gram of sulfur. What is the simple whole number ratio for the masses of lead that can make compounds with sulfur? (Write your answer ratio format. e.g: 5:2)
2 to 1
All samples of a specific substance have the same chemical composition. (T/F)
True
Who was the most influential philosopher when it came to the subject of the composition of the natural world?
Aristotle
Aspirin is a mixture of different compounds. (T/F)
True
Brittleness, malleability, ductility, and viscosity fall into the category of physical properties of matter. (T/F)
True
phase
any part of a sample with uniform composition and properties
Liquids are _____ than gases
denser
weight is _________ of location
dependent
hardness
determines how an element might be used
Water is 11.19% hydrogen and 88.81% oxygen by mass. Lake Superior contains about 1.2×1016 kg of water. What mass of hydrogen is contained in Lake Superior?
1.3 x10^15
List two areas where chemistry has helped surgical patients
-Artificial skin -sterile materials -stents
What contributions to modern chemistry were made by the alchemists?
-Periodic Table -inks -dyes -paints -leather tanning -ceramics -glass
How is research usually supported?
-grants -funds from colleges and universities (some of the studies take place there)
Why is gold considered to be valuable?
-it doesn't get destroyed or damaged -very rare -used as money
List two ways chemists help with issues related to lead contamination.
-measure the amount of lead in the soil, paint, plumbing, blood -and it is measured in more materials Chemists find ways to create efficient products that do not use lead. Chemists also study the impact the lead has had on humans and how to help.
List three things crops need for good growth.
-nutrients -water -protection from insects (predators)
pico (p)
0.000000000001 (10^-12)
nano (n)
0.000000001 (10^-9)
micro
0.000001 (10^-6)
milli (m)
0.001 (10^-3)
centi (c)
0.01 (10^-2)
deci (d)
0.1 (10^-1)
The mass ratio of H to O in water (H2O) is 1:8. What is the mass ratio of H to O in hydrogen peroxide (H2O2)?
1 to 16
n glucose (C6H12O6), the simplified ratio of C atoms to H atoms is
1 to 2
kilo (k)
1,000 (10^3)
mega (M)
1,000,000 (10^6)
giga (G)
1,000,000,000 (10^9)
A reaction of heating potassium permanganate produces potassium manganate, manganese dioxide and oxygen gas. Heat 15.8 g potassium permanganate until no more oxygen gas is given off. The remaining material has a mass of 14.2 g. What mass of oxygen gas was produced in the reaction? ___ g
1.6
In the compound nickel(II) sulfide, there is always 58.7 g of nickel for every 32.1 g of sulfur. What is the simplified ratio of nickel to sulfur?
1.83 to 1
SI system is based off of ______________?
10
deka (da)
10 (10^1)
A reaction of 12.640 g of copper oxide with 0.316 g hydrogen produces 2.844 g of water and X g of copper. X = ___ g
10.112
hecto (h)
100 (10^2)
What is a superconductor?
100% efficient conductor
1 kilometer = _______ meters
1000
When heated, calcium hydroxide and ammonium chloride react to produce ammonia gas, water vapor, and solid calcium chloride. Suppose 5.00g of calcium hydroxide and 10.00g of ammonium chloride are mixed in a test tube and heated until no more ammonia is given off. The remaining material in the test tube has a mass of 1.27 g. What is the total mass of ammonia and water vapor produced? ___ g
13.73
According to the law of conservation of mass, if an atom of element A has a mass of 2 units, while an atom of element B has a mass of 5 units, what would be the mass of the compound A3B2?
16 units
2.56 g of hydrogen reacts completely with 20.32 g of oxygen to form X g of water. X = ___g
22.88
There are two compounds of gold and chlorine. In one compound, there is 15.39 g of gold for every 2.77 g of chlorine. In the other compound, there is 7.74 g of gold for every 4.18 g of chlorine.Find the ratio of masses of gold in the two compounds.
3 to 1
Two compounds of phosphorus and fluorine have the following mass ratios.Compound 1: 10.14 g fluorine for every 3.38 g phosphorusCompound 2: 8.42 g fluorine for every 4.21 g phosphorusFind the whole number ratio of masses of fluorine in compound 1 to compound 2.
3 to 2
A reaction of 22.85 g of sodium hydroxide with 20.82 g of hydrogen chloride produces 10.29 g of water and X g of sodium chloride. X = ___ g
33.38
A neutral atom has 37 electrons. How many protons does the atom have?
37
The molecular formula for ethane is C2H6. What is the carbon:hydrogen mass ratio for ethane?
4 to 1
A reaction of heating calcium carbonate produces calcium oxide and carbon dioxide gas. Heat 10.0 g calcium carbonate until no more carbon dioxide gas is given off. The remaining material has a mass of 5.6 g. What mass of carbon dioxide gas was produced in the reaction? ___ g
4.4
What fraction of crops are grown using irrigation?
40%
A reaction between ammonia gas and chlorine gas produces ammonium chloride and nitrogen gas. A reaction of 17.0 g of ammonia with 26.6 g of chlorine gas gives off 3.50 g of nitrogen. What mass of ammonium chloride is formed in the reaction? ___ g
40.1
Calcium carbonate, CaCO3, decomposes when heated to calcium oxide (CaO) and carbon dioxide (CO2). If 100 g of calcium carbonate is allowed to decompose, 56 g of calcium oxide is produced. What mass of carbon dioxide is produced by the decomposition?
44
Serotonin (C10H12N2O) is a neurotransmitter. The ratio of C atoms to N atoms is _____
5 to 1
In carbon monoxide, there is always 1.33 g of oxygen for every 1 g of carbon. How many grams of carbon are in a 16.03 g sample of carbon monoxide? ____ g carbon
6.88
The percent by mass of sodium in table salt (NaCl) is 39.34 %. What is the percent by mass of chlorine?
60.66
In carbon dioxide, how many grams of oxygen would there be if there are 24 grams of carbon?
64
There are _______ basic SI base system units
7
Magnesium (24.30 g) reacts with hydrogen chloride (X g) to produce hydrogen gas (2.04 g) and magnesium chloride (96.90 g). How much hydrogen chloride was used in the reaction? ______ g HCl
74.42
Atoms of carbon-14 have ____ neutrons.
8
A statement best describes how protons were discovered?
A cathode ray tube revealed a ray of positive particles traveling in the opposite direction of negative electrons.
physical change
A change in a substance that does not involve a change in the identity of the substance
chemical change
A change in matter that produces one or more new substances (different composition)
physical property
A characteristic of a pure substance that can be observed without changing it into another substance
mixture
A combination of two or more substances that are not chemically combined, in any proportion
theory
A hypothesis that has been tested with a significant amount of data (why)
What is the difference between a hypothesis and a theory?
A hypothesis that is repeated multiple times with the same ending is turned into a theory / Hypothesis is a proposed explanation intended to be further tested. A theory is what is developed after testing to explain the results.
mass
A measure of the amount of matter that an object contains, SI base kilograms (kg)
weight
A measure of the force of gravity on an object
chemical symbol
A one or two letter representation of an element
filtration
A process that separates materials based on the size of their particles.
distillation
A process that separates the substances in a solution based on their boiling points
What is the difference between a theory and a law?
A theory is a repeated and confirmed hypothesis (with a why) while a law is a statement that is always true (even though there is not always a why) / Theory is often times the why and a law is always true but does not explain why.
What is an example of a physical change but not a chemical chemical change?
A water pipe freezes and cracks on a cold night
Who invented the first battery?
Alessandro Volta
Who invented dynamite?
Alfred Nobel
example of deductive reasoning
All men are mortal. Socrates is a man. Therefore, Socrates is mortal.
What product is not a heterogeneous mixture?
Ammonia
volume
Amount of space occupied by a sample of matter, SI base is cubic meter (m^3)
Hypothesis
An educated guess
What contribution to chemistry did Robert Boyle make?
Boyle's Gas Laws, created idea that small particles combine to form molecules
Who discovered the existence of the neutron?
Chadwick
Define "inductive reasoning" and give an example.
Collecting specific examples and drawing conclusions.
What would cause water to turn from a gas to a liquid?
Decreasing the water's temperature
A given chemical compound always contains the same elements in the exact same proportions by mass is the law of _____.
Definite proportions
Who was known as 'The Laughing Philosopher'?
Democritus
_____ introduced the idea of the atoms as basic building block of matter.
Democritus
What is pure research?
Done primarily to advance human understanding.
Explain how a hand-warmer works.
Exothermic Chemical reaction that releases thermal energy
A pure substance can be separated into components by physical methods. (T/F)
False
In mixtures, substances must combine in specific proportions (T/F)
False
Mixtures are all mixed uniformly and have an even composition throughout (T/F)
False
Titanium is softer than gold (T/F)
False
Who discovered the structure of insulin?
Fredrick Sanger
Sonia wanted to make ice pops. She filled cups with 150 mL of juice and put them in the freezer. How will freezing the juice affect its mass?
Freezing the juice will not change it's mass
______ can be highly compressed
Gas
Suppose you have three identical test tubes that contain equal masses of a solid, liquid, and gas form of the same substance. Which form of the substance has the largest volume and why?
Gas: It expands to fill the container
The mass ratio of hydrogen to oxygen in water (formula H2O) is 0.126 g hydrogen for every 1 g of oxygen. In another compound of hydrogen and oxygen called hydrogen peroxide, the mass ratio of hydrogen to oxygen is 0.063 g hydrogen for every 1 g of oxygen. What is a possible formula of hydrogen peroxide?
H2O2
example of inductive reasoning
Harold is a grandfather. Harold is bald. Therefore, all grandfathers are bald.
How did Aristotle improve the approach?
He was the first to make observations and he tried to understand what was happening / Carried out research and recorded data.
A _____ mixture consists of two or more phases.
Heterogeneous
Give one example of pure research.
How the universe formed? / Is there life on Mars?
Which of the following contains a single phase? I. substance II. homogeneous mixture III. heterogeneous mixture
I and II
When one or more substances undergo a chemical reaction, the:
Mass of the reactant decreases and the mass of the product increases but the total mass remains the same.
What chemical is missing in the diabetic patient?
Insulin
What is applied research?
Intended for a practical goal and application.
What is the health danger of breathing carbon monoxide?
It blocks oxygen from binding to hemoglobin.
Milk is uniformly mixed it contains several compounds--water, proteins, fats, and sugars. Is milk considered a substance or a mixture?
It is a mixture that can be separated by physical means
Why is gold considered valuable?
It is a very rare element, and is dangerous to mine
What happens to the lead in used car batteries?
It is recycled -it is put into a tank that separates it from the rest of the materials so it can be used again
Soil is a heterogeneous mixture. What best explains why?
It is unevenly mixed, so it does not have the exact same composition throughout the mixture.
Salt water is a homogeneous mixture. What best explains why?
It is uniformly mixed, so it has an even composition throughout.
which scientist discovered the electron?
JJ Thomson
metric prefixes come from _____ or _____ terms
Latin, Greek
A chemical compound is always found to be made up of the same elements combined together in the same fixed proportion by mass. This is known as the:
Law of definite proportions
area (A)
Length x Width (m^2)
The water cycle is a complex system. In it, water changes states. Sometimes it is a liquid. Sometimes it is a solid. Other times it can become a gas. What change occurs when water is boiled?
Liquid becomes a gas
What is the elixir of life?
Philosopher's stone (be able to turn metal into gold) thought to bring immortality
What is the relationship between the masses of protons and electrons?
Protons are much more massive than electrons.
Which of the following was/were used by the Greek philosophers in order to understand the world?
Reason
Before J.J. Thomson began gathering evidence about electrons in 1897, what did scientists know about atoms?
Scientists generally thought atoms were the smallest particles that could not be broken down any further.
Two examples of chemistry in daily life
Showering, cooking
When combined, iodine and tin were found to produce two different molecules. Both contained the same mass of tin, but one had twice as much iodine. The molecular formula for one of the molecules is SnI2 , what is the formula for the other molecule? (2 answers)
SnI or SnI4
Define "deductive reasoning" and give an example.
Specific prediction based on a general principle.
Who developed Kevlar?
Stephanie Kwolek
What was the first synthetic resin used for?
Sturdy and inexpensive dishware
Which statement(s) best describe why table sugar is considered a pure substance?
Sugar has the same chemical composition throughout, a bowl of sugar contains only one compound, and sugar cannot be separated further by physical means
What evidence from the cathode ray tube experiment support the claim that electrons have a negative charge?
The cathode ray bent away from a negatively charged plate. The cathode ray bent toward a positively charged plate.
Which of the following best describes how Thomson concluded that electrons are present in all atoms.
The charge-to-mass ratio of electrons is always the same constant, no matter which substances are used in the cathode ray tube.
Identify the law that explains the following observation: Nitrogen dioxide can be formed by reacting 14 grams of nitrogen with 32 grams of oxygen.
The law of definite proportions
Katie's teacher has asked her to identify an unknown substance. She thinks about the properties of matter that will help her identify the substance. She knows it is a colorless liquid. She thinks it may be water but knows there are many colorless liquids that are not water. What would inform Katie that the liquid is NOT water?
The liquid freezes at 32 degrees C
length
The measurement of the extent of something along its greatest dimension, SI base unit is meter (m)
Why do solids not change much when pressure is applied to them?
The particles in a solid are very closely packed
_______ energy is released when we burn natural gas.
Thermal
What kind of energy is released when we burn natural gas?
Thermal energy
What contributions were made by alchemists to chemistry today?
They laid the groundwork (production of gunpowder, ceramics, glass)
A mixture is not considered to be a pure substance. (T/F)
True
Dela is helping his Aunt Starr on an archeological dig. His aunt gives him a bucket containing sand, rocks, and artifacts. What is the best way for Dela to separate the sand from the other materials?
Use a screen to filter out the sand.
Are all solutions homogeneous mixtures?
Yes
Can homogeneous mixtures be separated into their components?
Yes
What happens when an electron is removed from an atom?
a positive charge remains
extensive property
a property that depends on the amount of matter in a sample
intensive property
a property that depends on the type of matter in a sample, not the amount of matter
The mass of a neutron is close to the mass of
a proton
scientific notation
a way to express numbers as the product of 2 numbers, coefficient multiplied by 10 to a power
Which property is NOT used to separate a mixture?
ability to undergo a chemical reaction
concentration (c)
amount/volume (mol/L)
What is electric current's SI base unit?
ampere (A)
(identify type of chemistry) measuring mercury in seawater
analytical chemistry
Zoe is using a spectrophotometer to precisely determine the levels of various chemicals in a sample of drinking water. Identify the type of chemistry.
analytical chemistry
What happens to the lead in car batteries?
batteries are taken to a plant where they are crushed, lead sinks to the bottom, is melted and used again
What did John Dalton contribute to the atomic theory?
believed all matter is made of atoms, all atoms of an element are alike, compounds form when atoms of different elements combine and chemical reactions involve rearranging atoms not a change in atoms
(identify type of chemistry) studying enzymes in cells
biochemistry
What blood test can be performed using material purchased from your local drugstore?
blood glucose test
Eliot is given a sample of unknown liquid to test in the laboratory. Eliot thinks that the liquid is water, but he isn't sure. What would be most helpful for Eliot to test in order to determine whether or not the liquid is water?
boiling point of the liquid
What is a hazard of lead?
brain damage, especially in children
What is the macroscopic world?
can be seen without a microscope (measured directly)
suspensions
can filter out, can see, heterogeneous, large particles
colloids
can't be filtered out, can see, homogeneous, medium particles
solutions
can't be filtered out, can't see, homogeneous, tiny particles
What is luminous intensity's SI base unit?
candela (cd)
What is the microscopic world?
cannot be seen without a microscope
What method would likely be used to separate a mixture of colored inks?
chromatography
What separation technique involves passing the mixture through a medium in which the components move at different rates?
chromatography
______ separates components in a mixture at different rates as they pass through a medium.
chromatography
How did Aristotle improve the approach of old philosophers when studying the material world?
collected his data and made systematic observations to understand what he was seeing
Butter is a mixture of proteins and fats that does not separate out when left alone. What type of mixture is butter?
colloid
Examples of intensive properties are ____ and _____
color, temperature
The "clusters" of Democritus are like what kind of material that we know of today?
compounds
During a chemical reaction, the law of _______ _______ states that the total mass of the products must be equal to the total mass of the reactant.
conservation of mass
solid
definite shape, definite volume, particles vibrate on fixed axes