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CH304K Test One
Terms in this set (56)
The 2016 Nobel Prize Award in chemistry was awarded for:
A) developing methods to make molecular machines
B) discovering gravitational waves
C) the total synthesis of vitamin B12
D) the discovery of graphene
In the 1950s chemists began tinkering with noncovalently interlocking molecules to make tiny molecular chains. What the major limitation of synthesizing these early molecular chains?
A) they could only be made in extremely small quantities
B) they were too weak to do work
C) they were unstable and would rapidly decompose
D) they required the use of dangerous chemicals
In 1983 Sauvage et al had a breakthrough in the synthesis of molecular chains - what was it?
A) he used a copper ion to template the reaction increasing the yield dramatically
B) he developed a method of lithography to construct the molecular chains of the surface of a silicon wafer increasing the yield
C) he used a biological enzyme to control the 3d orientation of chains increasing the yield
D) he strengthened the molecular chain by annealing it with gold ions
Interlocking molecules using noncovalent chemistry into complex chains and knots is a field of chemistry called:
A) topological chemistry
B) mechanical chemistry
C) machine chemistry
D) wheel and axel chemistry
Sauvage made important contributions to the synthesis of molecular chains called catenanes. Stoddart took thing further by developing:
A) rotaxanes: molecular rings that are threaded on a molecular axle
B) making longer more mechanically strong ring structures
C) making molecular chains that could be used to perform mechanical work
D) making a molecular container molecule that could store gases
Feringa's major contribution for the 2016 Nobel Prize was:
A) developing a molecular motor that only spun in single direction
B) developing a molecular needle and thread
C) developing a single molecule combustion engine
D) developing a more environmentally friendly route to catenanes
What are some current technologies we use in everyday life that use molecular machines of the type the 2016 Nobel Prize was awarded for?
B) cellular phones
C) allergy medication
The same volume of cheap ice cream will typically feel a lot lighter than the same volume of expensive ice cream - Why?
A) cheap ice cream contains a lot of air making it less dense
B) the packaging of expensive ice cream weighs more
C) cheap ice cream contains more fat making it less dense
D) cheap ice cream contains more water making it less dense
Ice cream has three distinct phases: water, oil and air. The oil and air are dispersed in the water. This type of system is best described as:
A) an emulsion
B) an amorphous solid
C) a gelated flowem
D) a frozen matrix
The additive that stops the oil, water and air phases of ice cream from separating out is called an:
Ice cream contains stabilizers such as carrageenan, sodium alginate or xanthan gum. The purpose of such stabilizers is to:
A) prevent the formation of large ice crystals
B) raise the freezing point
C) solubilize the fat in water
D) lower the freezing point
The primary reason ice cream freezes at a lower temperature than water is:
A) dissolving things in water lowers its freezing point
B) emulsions inherently freeze at lower temperatures than water
C) stabilizers lower the freezing point
D) emulsifiers contain crystalline mesophases that lower the temperature of the mixture
Photosynthesis is the process in which organisms, such as plants and cyanobacteria, take ______ and _____ and make carbohydrates and _____ .
CO2, H2O, O2
What is the byproduct of photosynthesis?
A) CO2 (carbon dioxide)
B) CH4 (methane)
C) O2 (oxygen)
D) N2 (nitrogen)
What are some of the reactions that oxygen (O2) can do? (list all that apply)
A) React with metals to from metal oxides like Fe2O3 (iron oxide, rust)
B) Burn with an appropriate fuel source
C) React with the nitrogenase enzyme in cyanobacteria, preventing its function
A, B, C
What does the nitrogenase enzyme do in cyanobacteria?
A) Converts nitrogen (N2) to ammonia (NH3) so the organism can use it
B) Convert ammonia (NH3) to nitrogen (N2) that the organism expels
C) Takes nitrogen (N2) to other parts of the organism, similar to how red blood cells move oxygen (O2) in animals
What is the term for the amount of light that is reflected by a surface?
C) radiative gravity
What has the highest albedo?
B) fresh snow
D) rain forest
What happens as the early earth begins to cool down more?
A) It begins to rain more, diminishing cloud cover.
B) More water begins to freeze, increasing the earth's albedo.
C) The oceans begin to freeze, stopping convection currents that would warm the surface.
What happens as the albedo of the early earth increases?
A) More energy is reflected by the earth's surface and gets trapped between the ground and clouds, heating the atmosphere.
B) Less energy reaches cyanobacteria and they begin to die out, increasing CO2 in the atmosphere.
C) The earth absorbs less energy from the sun, cooling it down.
Where did life survive during the first ice age 2.5 billion years ago?
A) Deep in the ocean near hydrothermal vents
B) Frozen dorment within the ice
C) All life died out during the ice age and had to start over afterwards
What ends the first ice age?
A) Volcanoes erupt and lava melts the ice and warms the planet
B) Volcanoes release enough CO2 to increase the greenhouse effect, warming the earth
C) The earth drifts slightly closer to the sun, warming it
Which of the following is another common way, besides photosynthesis, in which CO2 (carbon dioxide) is naturally removed from the atmosphere?
A) Atmoshperic outgassing, where molecules of CO2 have enough velocity to leave the earth's atmosphere
B) Formation of carbonate rock from CO2 dissolved in water
C) Spontaneous decomposition of the gas to form carbon graphite (C) and oxygen gas (O2)
What conditions allowed for the development of multicellular organisms?
A) Cyanobacteria finally died off, allowing for newer and different organisms to develop
B) "Life, uh, finds a way"
C) The high O2 content of the atmosphere, which can provide more energy for life processes
We often refer to O2, diatomic oxygen, as just 'oxygen', because it is the most common form of that element. There is another form of elemental oxygen, O3, which is called ozone. Diatomic oxygen and ozone are both _________ of elemental oxygen.
What needed to happen before life could move from the oceans onto land?
A) Volcanic ash from the recent erruptions that ended the ice age needed to dissipate
B) The ozone layer needed to form, to protect life from harmful UV rays
C) The continents need to be formed for there to even be land to move to
D) Toxic gas molecules from cyanobacteria had to be removed from the air
A) cannot be broken down any further by chemical means.
B) is two or more different elements chemical bonded together.
C) is two or more of the same element bonded together.
A substance that consists of only one type of element or one type of molecule is called a ____________.
When chemistry was still a very young science it was important to be able to determine whether something was a pure substance or a mixture because:
A) Pure substances contained phlogist, which could be extracted to create medicinal compounds.
B) The King of England had issued a stiff tarrif on pure substances creating an economic driving force to develop methods for determining whether or not a substance was pure or not.
C) The elements were still being discovered and there was still debate over what substances were pure and what substances were mixtures (for example air).
What is the largest component of air?
A) oxygen (O2)
B) carbon dioxide (CO2)
C) nitrogen (N2)
D) water (H2O)
D) argon (Ar)
How old is the universe?
13.8 billion years
How old is the earth?
4.5 billion years
How old is life on Earth?
4 billion years
When was LUCA?
3.8-3.5 billion years ago
What best describes how the greenhouse effect works on Earth?
A) It's when visible light emitted by the surface of the Earth reflects off of greenhouse gases in the atmosphere and becomes trapped
B) It's when greenhouse gases in the atmosphere emit heat that become trapped in the troposphere
C) It's when infrared radiation (ie. heat) gets trapped because it can't pass through certain gas molecules
The 'young Sun paradox' is:
A) that 4 billion years ago the Sun wasn't hot enough for the surface of Earth to have liquid water.
B) that isotopic dating of the Sun reveals that is 1 billion years younger than Earth.
C) that 4.5 billion years ago the early Sun was too unstable to cause the solar nebula to accrete into planets.
D) that the early Sun was too small to fuse hydrogen into helium and should have collapsed.
The most likely solution to the 'young Sun paradox' is:
A) Earth's surface temperature was raised because the core of the planet had not fully cooled.
B) The early atmosphere on Earth was full of greenhouse gases that helped keep the surface of the planet warm.
C) Life evolved early on Earth and the biochemical reactions of life helped to generate heat keeping the surface of the planet warm.
The concentration of carbon dioxide in the current atmosphere is closest to:
Rock, sediment, and ice core sampling allow us to collect data on atmospheric and geologic conditions from millions to billions of years ago.
How is CO2 concentration determined from ice core samples?
A) Analysis of gas content from bubbles in the ice
B) The color of the ice when it was frozen
C) By melting the ice and measuring its pH
What do the light and dark regions in ice core samples represent?
A) Regular fluxuations in CO2 concentration in the air
B) 1 year of ice formation, cycling between summer and winter
C) Nothing, the light and dark regions are marks from when the core was drilled out
What is the term that describes atoms that have the same number of protons, but a different number of neutrons?
How many protons are in one atom of ¹⁸₈O?
How many neutrons are in one atom of ¹⁸₈O?
Suppose you have 100 grams of a radioactive substance with a half life of 1 week. How much of the original substance will you have after 1 week?
A) 200 grams
B) 100 grams
C) 50 grams
D) 25 grams
E) 0 grams
Suppose you have 100 grams of a radioactive substance with a half life of 1 week. How much of the original substance will you have after 2 weeks?
A) 200 grams
B) 100 grams
C) 50 grams
D) 25 grams
The amount of carbon-14 (146C) in the atmosphere is _______. ________ organisms are in constant equilibrium with this carbon-14. Because carbon-14 is _______, we can use its half life to determine how long ago an organism died.
Constant, living, radioactive
What has a higher boiling temperature, water that contains 16O (oxygen-16) or water that contains 18O (oxygen-18)?
A) 18O water
B) 16O water
𝛿18O (delta oxygen-18) is used to represent a very small change in 18O content. If 𝛿18O has a negative value, what does that mean?
A) oxygen-18 content is increasing
B) oxygen-18 content is decreasing
As temperature increases, 18O content in liquid water will ___________.
As temperature ___________, 18O content in liquid water will increase.
If we measure that atmospheric water has an increasing amount of 18O, then we can know that 18O content in liquid water has ________, because the temperature has _______ .
1H makes up roughly 99.99% of all hydrogen atoms. 2H makes up the remaining 0.01%. 2H is sometimes also called deuterium and abbreviated as just D.
Water can be made with deuterium instead of regular hydrogen and is commonly known simply as "heavy water" (D2O) Would you expect the boiling point of heavy water to be greater, less, or the same as normal water made with 1H?
A) greater than H2O
B) the same as H2O
C) less than H2O
Air is a single element that is indestructible and unalterable. True or false?
Around what time did we realize air is a mixture of gases?
The primary components of the current atmosphere are?
N2, O2, Ar