Monday, January 14, 2019
Saturday, May 28, 2016
Attention Mr B's Chem and Physics Students
Below you will find the complete reviews for the semester final.
I will be back Sunday morning to post selected answers and to answer your questions.
In the meantime, answer all questions if you can, and help each other by posting in the comments.
Good luck!!
I will be back Sunday morning to post selected answers and to answer your questions.
In the meantime, answer all questions if you can, and help each other by posting in the comments.
Good luck!!
Chemistry Final Review 2016
A piece of silver releases 202.8 J of
heat while cooling 65.0 °C. What is the mass of the sample? Silver has a specific heat of 0.240 J/g °C. 13.0 g
What is the specific heat of gold if a
38.0 gram bracelet releases 460.8 Joules of heat energy and the increase in
temperature is 94.0 °C? .129 J/g C
What is the term for the amount of energy
absorbed or released in a chemical reaction? Heat of Reaction
How many joules of heat is needed to heat 68.00 grams of aluminum foil from 55.00
°C to 93.00 °C if aluminum has a specific heat of 0.90 J/g °C? 2326 J
Which unit listed below is used to
measure solution concentration in chemistry?
During an ____endothermic___________ reaction,
heat content in the surroundings decreases because the reaction absorbs heat
energy.
Write the thermochemical equation that
shows that the combustion of methane is an exothermic reaction.
What is the molarity of a solution that
contains 5.80 grams of nickel (II) nitrate in 500. mL?
As the average kinetic energy increases
in a material _thermal ___ energy also increases.
When elements bond together they use
energy in the bonding process. What is this energy process called? chemical energy
Write the neutralization reaction for
H2SO4(aq) +
NaOH(aq) →
How
many grams of sodium hydroxide are needed to make 250. mL of a 7.80 M solution? 78 grams
Students were given four small bottles
marked "A," "B," "C," and "D." They
were told that each bottle contained one of the following solutions: HNO3, NaOH,
AgNO3, and CaCl2. Their assignment was to identify the contents of each bottle.
The students tested a small amount of each solution with a piece of blue litmus
paper moistened with distilled water. Only solution B turned the blue litmus
paper red. Which solution was in the bottle marked "B"?
Students tested an unknown solution with
a pH meter. The meter indicated that the solution has a pH of 10.3. Based on
this information, what can the students correctly infer about the unknown
solution? It is basic
The reading of a pH meter is a measure of
_______H+_________________ion
concentration.
The base Ba(OH)2
neutralizes the acid H2SO4.
Which salt is produced?
Phosphoric acid, H3PO4, is
a weak electrolyte because it dissociates _______incompletely___________ in solution.
Which unit listed below is used to
measure solution concentration in chemistry? Molarity
Charles' law describes the relationship
between which two quantities?
The pressure of a sample of dry air is
held constant 2.25 atm
while the temperature is decreased from 100. °C to 7.0 °C. The original volume
of the sample is 43 L. Which of the following is closest to the final volume of
the sample?
A sample of methane gas (CH4) with a mass of 58 g is kept in a 1500
mL container at a temperature of 100. °C. What is the pressure of the gas?
The volume of as in a balloon is 1.90 L
at 21.0 °C. The balloon is heated, causing it to expand to a volume of 5.70 L.
What is the new temperature of the gas inside the balloon?
A student burns 1.50 mol C3H8
according to the following reaction: C3H8 + 5O2 3CO2 + 4H2O.
How many grams of CO2 are produced?
Solid zinc oxide is added to hydrochloric acid
to form zinc chloride in water. How many moles of zinc chloride will be
produced when 112 grams of is used?
What is a balanced chemical equation
describing the formation of water?
How many molecules are in 2.50 moles of H2O?
How many atoms are present in 179.0 g of
iridium?
What is a mole in chemistry terms?
SI unit for the amount of a substance
What is the molar mass of carbon?
What is the molar mass of KBr?
What is the molar mass of CO2?
How many atoms are in a tetrahedral
molecule? 5
What is the molecular shape of a CCl4 molecule? tetrahedral
Draw the electron-dot diagram for Br2(l)?
Draw the Lewis Dot diagram for CH4?
What is the formula for copper (I) oxide?
What is the chemical formula for disulfur decafluoride?
What is the correct formula for mercury
(II) chloride?
What is the name of the compound N2O3?
What is the name of the compound AlPO4?
What is the trend of ionic radius?
What is the correct electron
configuration for manganese?
What is the ground state electron
configuration for arsenic?
Describe the properties of noble gases.
The number of valence electrons in Group
2 elements is ____2_____.
As
the atomic number on the Periodic Table increases, the number of electrons
___________Increases_________.
Physics Final Review 2016
What does a transformer do?
What type of decoding of a credit card does the machine do when you swipe?
A home security system has a steel disk on the door next to a sensor coil on the door frame. When the door is opened, what characteristic changes in the coil to set off alarm?
Label the poles of the two bar magnets.
What is the force between two 1.0 X 10-5 C charges separated by 2.0 m?
What happens to resistance as the wire carrying a current gets larger?
This means the resistance is ______________ proportional to the cross-sectional area.
Glass, Copper, Wood, and Rubber... Which will distribute electric charge better?
What is the current in this circuit?
Is it the same everywhere in the circuit?
How can I lower the current in this circuit?
What is entropy?
How does phase change affect entropy?
What does the first law of thermodynamics state regarding the internal energy of a system? (look in your notes for the formula or definition... either will give you the answer)
Why is the motor on a refrigerator required to do work?
(What is the refrigerator doing, pumping cold air in?
Only about 15% of the energy released in a combustion engine is converted to mechanical energy. What happens to the rest?
Which direction are the oscillations of a transverse wave? Perpendicular to wave direction
Which direction are the oscillations of a longitudinal wave? Parallel to wave direction
Which type of wave is a light wave? transverse
Which type of wave is a sound wave? longitudinal
Which type of wave is an ocean wave? transverse
What is the difference between a mechanical wave and an electromagnetic wave?
mechanical wave needs a medium, an electromagnetic wave moves energy not matter (so it can travel in a vacuum)
Does the medium a wave is travelling through affect a wave? yes it changes the speed
If so, how? (Does it change the direction of the oscillation? Does it change the speed? Does it change the wavelength?)
What is the wavelength of a wave that travels at a speed of 2.0 × 108 m/s and has a frequency of 3.5 × 1016 Hz?
What did we first use in the classroom to demonstrate a longitudinal wave?
the spring where it is stretched and squished
Which type of electromagnetic wave travels the fastest? (radio waves, X-rays, Gamma Rays, Visible light, infrared light, etc.) They all travel the same speed in a vacuum
How fast does it travel? the speed of light C
Someone fires up their Harley Davidson Fatboy motorcycle in the Grand Canyon. She hears the rumbling echo of those pipes three seconds later. If the speed of sound is 340 m/s, how far away was the canyon wall that produced the echo?
510 meters (1.5 seconds to the wall, 1.5 seconds back..)
What is the purpose of the control rods in a Nuclear Reactor?
How do they do this? to slow or limit the reaction by absorbing neutrons
What is it called when nuclei are split in a nuclear reaction? Is this type of reaction used in nuclear energy production? fission, yes
Does it release high, medium, or low amounts of energy compared to other types of energy producing reactions? high energy
What property of light allow lenses in microscopes and telescopes to work?
refraction
If a Dr. Pepper bottle is held up in front of a flat mirror, how will the image appear? (larger, smaller, the same? inverted? closer or farther away?)
upright, same size, equal distance from mirror to bottle and mirror to image
Will the image in the mirror still make you thirsty for Dr. Pepper? most definitely (this question is not on the test though)
Current is the flow of __________? electrons
What type of decoding of a credit card does the machine do when you swipe?
A home security system has a steel disk on the door next to a sensor coil on the door frame. When the door is opened, what characteristic changes in the coil to set off alarm?
Label the poles of the two bar magnets.
What is the force between two 1.0 X 10-5 C charges separated by 2.0 m?
What happens to resistance as the wire carrying a current gets larger?
This means the resistance is ______________ proportional to the cross-sectional area.
Glass, Copper, Wood, and Rubber... Which will distribute electric charge better?
What is the current in this circuit?
Is it the same everywhere in the circuit?
How can I lower the current in this circuit?
What is entropy?
How does phase change affect entropy?
What does the first law of thermodynamics state regarding the internal energy of a system? (look in your notes for the formula or definition... either will give you the answer)
Why is the motor on a refrigerator required to do work?
(What is the refrigerator doing, pumping cold air in?
Only about 15% of the energy released in a combustion engine is converted to mechanical energy. What happens to the rest?
Which direction are the oscillations of a transverse wave? Perpendicular to wave direction
Which direction are the oscillations of a longitudinal wave? Parallel to wave direction
Which type of wave is a light wave? transverse
Which type of wave is a sound wave? longitudinal
Which type of wave is an ocean wave? transverse
What is the difference between a mechanical wave and an electromagnetic wave?
mechanical wave needs a medium, an electromagnetic wave moves energy not matter (so it can travel in a vacuum)
Does the medium a wave is travelling through affect a wave? yes it changes the speed
If so, how? (Does it change the direction of the oscillation? Does it change the speed? Does it change the wavelength?)
What is the wavelength of a wave that travels at a speed of 2.0 × 108 m/s and has a frequency of 3.5 × 1016 Hz?
What did we first use in the classroom to demonstrate a longitudinal wave?
the spring where it is stretched and squished
Which type of electromagnetic wave travels the fastest? (radio waves, X-rays, Gamma Rays, Visible light, infrared light, etc.) They all travel the same speed in a vacuum
How fast does it travel? the speed of light C
Someone fires up their Harley Davidson Fatboy motorcycle in the Grand Canyon. She hears the rumbling echo of those pipes three seconds later. If the speed of sound is 340 m/s, how far away was the canyon wall that produced the echo?
510 meters (1.5 seconds to the wall, 1.5 seconds back..)
What is the purpose of the control rods in a Nuclear Reactor?
How do they do this? to slow or limit the reaction by absorbing neutrons
What is it called when nuclei are split in a nuclear reaction? Is this type of reaction used in nuclear energy production? fission, yes
Does it release high, medium, or low amounts of energy compared to other types of energy producing reactions? high energy
What property of light allow lenses in microscopes and telescopes to work?
refraction
If a Dr. Pepper bottle is held up in front of a flat mirror, how will the image appear? (larger, smaller, the same? inverted? closer or farther away?)
upright, same size, equal distance from mirror to bottle and mirror to image
Will the image in the mirror still make you thirsty for Dr. Pepper? most definitely (this question is not on the test though)
Current is the flow of __________? electrons
Sunday, October 27, 2013
We are now Interstellar Travelers (er.. so to speak)
Although there are no real, live humans on board, the Voyager I spacecraft has now passed out of our own solar system. One of the things that I found fascinating about this news is that it took a couple of months for the scientists working on the Voyager mission to confirm that it had passed out of the solar system. This is because it is not a simple matter of looking out the window and seeing a "you are leaving the solar system, come again soon" sign. There is data that is being sent back from the craft that must be meticulously analyzed to determine it's position.
Now... a question I would ask my Physics class (we are studying Newton's Laws of motion), or anyone who has seen the film "Gravity": Why does the craft use so little power as it travels through (and now out of) the solar system?
Thursday, October 11, 2012
Nobel is a Warning for U.S. Universities
The Nobel prize in physiology or medicine has been awarded.
The recepients were, of course, very deserving, and their work is a very good basis for medicine that will one day drastically change the outlook of those with certain medical problems and diseases.
However, I wanted to point out that the ground breaking research was done in England and in Japan, none at any U.S. university. Now, I am not suggesting that ALL breakthroughs must happen at U.S. institutions. I would point out, though, that our university system is still the top in the world with good sums spent on research, and attracting the brightest minds from around the world to come study, but also to contribute to our body of knowledge.
The fact that this research was not done in the U.S. is not disturbing, but the fact that it could not be done in the U.S. because of restrictions on stem cell research IS. Politicians and lobbyists should not be controlling where research goes. It should be up to the scientists and doctors who have ethics committees, and a much, much better understanding of the science behind the research.
The recepients were, of course, very deserving, and their work is a very good basis for medicine that will one day drastically change the outlook of those with certain medical problems and diseases.
However, I wanted to point out that the ground breaking research was done in England and in Japan, none at any U.S. university. Now, I am not suggesting that ALL breakthroughs must happen at U.S. institutions. I would point out, though, that our university system is still the top in the world with good sums spent on research, and attracting the brightest minds from around the world to come study, but also to contribute to our body of knowledge.
The fact that this research was not done in the U.S. is not disturbing, but the fact that it could not be done in the U.S. because of restrictions on stem cell research IS. Politicians and lobbyists should not be controlling where research goes. It should be up to the scientists and doctors who have ethics committees, and a much, much better understanding of the science behind the research.
Monday, September 10, 2012
Problems Loom for Caribbean Coral Reefs
In fact, according to a report by the International Union for the Conservation of Nature (IUCN), many Caribbean reefs are already in dire straights.
The cause of the the desperate situation for the reefs is management which includes fishing regulations that keep the numbers of fish critical to the health of the reef up. Another cause is climate change which has caused the temperature of the waters to rise, and most reef building organisms have a small range of tolerance for water temperature.
If we can get some sensible regulations in place and enforce regulations, some reefs in other parts of the world have shown a great resilience in their return to health. However, it is extremely
Photo by ThinkP. Creative Commons License. difficult to get these things in order, and it may be too late for the reefs.
Although the reefs in the 60s and 70s had "50-60% live coverage", they are comparing to other reefs today with only around 30% live coverage and considered "relatively intact", with the Caribbean reefs still looking grim with less than 10% live coverage. I believe it is telling that we consider a reef that is 70% dead reflective of something relatively intact. But however they measure it, things are looking very bleak for Caribbean reefs.
National Geographic's Christine Dell'Amore has an article about the report released at the IUCN World Conservation Congress going on in South Korea.
If we can get some sensible regulations in place and enforce regulations, some reefs in other parts of the world have shown a great resilience in their return to health. However, it is extremely
Photo by ThinkP. Creative Commons License. difficult to get these things in order, and it may be too late for the reefs.
Although the reefs in the 60s and 70s had "50-60% live coverage", they are comparing to other reefs today with only around 30% live coverage and considered "relatively intact", with the Caribbean reefs still looking grim with less than 10% live coverage. I believe it is telling that we consider a reef that is 70% dead reflective of something relatively intact. But however they measure it, things are looking very bleak for Caribbean reefs.
National Geographic's Christine Dell'Amore has an article about the report released at the IUCN World Conservation Congress going on in South Korea.
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