Thursday
March 5, 2015

Posts by morgan


Total # Posts: 665

Chemistry
a) A current of 1.50 Amperes passes through a solution of AgNO3 for 3.0 hours. What mass, in grams, of silver collects on the cathode? (molar mass of silver = 107.9 g/mol) b) How many seconds would it take to collect 100 g of silver to collect on the cathode if 1.50 Amperes ...
March 5, 2015

chemistry
1. Many types of spectrophotometers produce graphs containing a base line with peaks. How are the peaks seen on the graphs produced by a spectrometer used in identifying substances? 2. If the analysis of a substance by using spectroscopy shows characteristic peaks, how does ...
March 2, 2015

Chemistry
Calculate the heat of reaction (ΔHrxn) for the following reactions, using heats of formation (ΔHf). Show your work. Refer to a table of heats of formation in your textbook as needed. 5O2(g) + 4NH3(g) → 6H2O(g) + 4NO(g)
March 1, 2015

chemistry
To interpret and compare heats of reaction (Hrxn), standard states must be used. What are the standard states for a gas, an aqueous solution, and a pure substance? Why are they important?
March 1, 2015

chemistry
1. Outline how you would use a calorimeter to determine the enthalpy of fusion of ice. 2. Suppose the enthalpy of fusion of ice determined from your experiment is lower than the accepted value. List three possible causes of the difference in value. Explain how each cause ...
March 1, 2015

physics
A fighter pilot is exposed to an acceleration of 3g in the horizontal direction during takeoff. Knowing that 1g=9.8 m/s2 and that the mass of the fighter pilot is 63.6 kg, what force (in Newtons) does the fighter pilot experience in the horizontal direction? This is the force ...
February 25, 2015

Chemistry
HCl is a gas at room temperature and does not conduct electricity. Yet when dissolved in water, the solution becomes an excellent conductor. Classify HCl as metallic, ionic, molecular or covalent network, and explain why HCl would conduct electricity in an aqueous solution.
February 25, 2015

chemistry
I ned these classified as metallic, ionic, molecular or covalent network and two reasons why. Aluminum Ascorbic acid Graphite Paraffin Palmitic acid Sodium chloride Sucrose Water
February 25, 2015

chemistry
Are acids like ascorbic acid and palmitic acid ionic, molecular, or covalent network compounds
February 25, 2015

Chemistry
Lets say you melted palmitic acid, paraffin, and sucrose. While they be good conductors, poor conductors, or will they not be able to conduct electricity.
February 25, 2015

Chemistry
In general, do transition metals or main group elements tend to have higher melting points? According to a article, the FeCoNi alloy tended to have a uniform structure when only Fe, Co, and Ni were included. With Al and Si, however, it had more segregation in its structure. ...
February 23, 2015

chemistry
I have questions but I don't understand this passage. Could you give a summery? Here are the question 1. One problem the researchers faced was an uncertainty about whether the signals observed in certain mass spectrometry data were, in fact, due to lead isotopes. Explain ...
February 20, 2015

Chemistry
The balanced net ionic equation resulting from addition of aqueous hydrochloric acid to solid chromium(III) hydroxide is: A. Cr(OH)3 (s) + 3 HCl (aq) 3 H2O (l) + CrCl3 (aq) B. Cr(OH)3 (s) + 3 Cl- (aq) 3 OH- (l) + CrCl3 (aq) C. Cr(OH)3 (s) + 3 H+ (aq) + 3 Cl- (aq) 3 H2O (l) + ...
February 20, 2015

chemistry
Describe how to prepare 1 L of a 0.5 M solution of cobalt chloride hexahydrate (CoCl2 6H2O). Be sure to identify the labware shown above (flask and a scale), explain your reasoning, and show any calculations.
February 20, 2015

Chemistry
Use this reaction for this question: 4NH3 (g) + 2O2 (g) 4NO (g) + 6H2 (g); H = -905 J. Which statement is true about the reaction above? A. G is negative at all temperatures. B. S is negative and G is positive. C. S is negative and G is negative. D. G is positive at all ...
February 20, 2015

math(5th grade)
This is a tricky question but I think I understand 1 trip, both geese 2. two bags of corn, but he has to take the geese back with him 3. the dog and the other bag of corn 4. He has to go back to get the geese So he need to cross the river eight times.
February 20, 2015

chemistry
A particular photon has a wavelength of approximately 2 x 10-7m. What is the energy, in joules, associated with this photon? A. More information is needed. B. 4 x 10-32 C. 1 x 10-18 D. 1 x 1018 E. 1.5 x 1015
February 20, 2015

chemistry
Given the following information about electronegativity, which binary compound would form covelant bonds with the greatest polarity? Element Electronegativity H 2.1 Li 1.0 S 2.5 Al 1.5 F 4.0 Cl 3.0 A. HCl B. LiF C. H2S D. AlH3
February 19, 2015

Chemistry
I believe the reduction values are .15 (copper) and -.25 (nickel)
February 19, 2015

Chemistry
Suppose a galvanic cell contains one nickel electrode and one copper electrode. At 25°C, nickel has a negative reduction potential and copper has a positive reduction potential. At which electrode will reduction occur? Explain. I believe the copper will be oxidized and the...
February 19, 2015

chemistry
Thank doesn't help. I posted the question because I don't understand how to compare the electronegativity when there are molecules like AlH3.
February 19, 2015

chemistry
Given the following information about electronegativity, which binary compound would form covelant bonds with the greatest polarity? Element Electronegativity H 2.1 Li 1.0 S 2.5 Al 1.5 F 4.0 Cl 3.0 A. HCl B. LiF C. H2S D. AlH3
February 19, 2015

chemistry
If BH3 formed the trigonal planar molecule shown in the image below, which statement would best describe BH3? A. Boron does not contain a complete octet of electrons. B. BH3 would orient in an electric field. C. BH3 is a polar molecule. D. BH3 forms four bonds around the ...
February 18, 2015

Chemistry/BrBob222 please read
the answer is d I illuminated a and b because I knew that Tf has to be subtracted by ti. Next I illustrated b because I knew the mass had to be that of water or the total. FInally, I used the formal for c before and my number was to high so division made sense I hope you can ...
February 18, 2015

Chemistry
Should I go with c or d?
February 18, 2015

Chemistry
You want to determine the heat of reaction when a sodium chloride solution is formed using a 10.0 g sample of NaCl(s) and 50.0 mL of water in a coffee cup calorimeter. Which of the following equations would you use? Assume the specific heat of the solution is the same as the ...
February 18, 2015

chemistry
I think the answer could be a. What do you think?
February 18, 2015

chemistry
Why is there a decrease in electron affinity going from lithium to sodium? A. There is a stronger nuclear charge, with no additional shielding electrons or number of shells. B. There are fewer spaces in the valence shell in which to place the added electron. C. The nucleus has...
February 18, 2015

chemistry
Calculate the change in enthalpy produced by dissolving 14.3 g of NaOH in 65.0 g of water if the temperature increases 49.1°C and the specific heat of water is 4.18 J/g°C I believe you multiply 4.18, 65.0, and 49.1. Am I correct
February 16, 2015

Chemistry
I need to make an Orbital diagram for Li2O. Could you help me find a helpful website or something?
February 11, 2015

chemistry
How can Coulomb's law explain the distribution of electrons.
February 10, 2015

Chemistry
lets say you have an F atom and an Ne+ ion. Which is more stable
February 10, 2015

Physics
A bullet with a velocity of 200 m/s is shot at a 2-kg block resting on a horizontal frictionless surface. The bullet imbeds in the block and the bullet-block system slides across the surface with a speed of 5 m/s. A) what is the mass of the bullet? B)The coefficient of ...
February 10, 2015

Physics
A 1000 kg car moving at 27 m/s from left to right collides head-on with a 1500 kg car moving at 30 m/s right to left. A) Determine the magnitude and direction of the velocity of the wreckage after the collision. B) If a 1000 kg car moving at 36 m/s from left to right collides...
February 10, 2015

chemistry
2. Create a visual representation of ionic substances to connect the microscopic structure of ionic substances to each of the following macroscopic properties. a. Solubility in polar compounds (1 point) b. Brittleness (1 point) Please explain how to do this. I know they want ...
February 7, 2015

chemistry
I am having some chemistry problems. 3. The graph compares the 1s orbital energies for the F atom (Z = 9), the Ne+ ion (Z = 10), and the Na++ ion (Z = 11). (the graph shows F having an Orbital Energy of 692.45, Ne+ with 47.74, and Na++ with 33.52) a. How many electrons does ...
February 7, 2015

chemistry
2. Create a visual representation of ionic substances to connect the microscopic structure of ionic substances to each of the following macroscopic properties. a. Solubility in polar compounds (1 point) b. Brittleness (1 point)
February 6, 2015

chemistry due soon
I am having some chemistry problems. 3. The graph compares the 1s orbital energies for the F atom (Z = 9), the Ne+ ion (Z = 10), and the Na++ ion (Z = 11). (the graph shows F having an Orbital Energy of 692.45, Ne+ with 47.74, and Na++ with 33.52) a. How many electrons does ...
February 6, 2015

Chemistry due soon
I am having some chemistry problems. 3. The graph compares the 1s orbital energies for the F atom (Z = 9), the Ne+ ion (Z = 10), and the Na++ ion (Z = 11). (the graph shows F having an Orbital Energy of 692.45, Ne+ with 47.74, and Na++ with 33.52) a. How many electrons does ...
February 3, 2015

chemistry
never mine I got it
February 3, 2015

chemistry
1. Write the electron configuration for each atom or ion. Then explain the distribution of electrons among energy levels. Ca, Be2+, and Br- I already found the electron configurations but I don't understand the second part of the question.(Then explain the distribution of ...
February 3, 2015

chemistry
I am having some chemistry problems. 3. The graph compares the 1s orbital energies for the F atom (Z = 9), the Ne+ ion (Z = 10), and the Na++ ion (Z = 11). (the graph shows F having an Orbital Energy of 692.45, Ne+ with 47.74, and Na++ with 33.52) a. How many electrons does ...
February 3, 2015

Chemistry
I think F and Na+ have nine but I am not sure about Na++
January 31, 2015

Chemistry
Unit 4
January 31, 2015

Chemistry
I am having some chemistry problems. 3. The graph compares the 1s orbital energies for the F atom (Z = 9), the Ne+ ion (Z = 10), and the Na++ ion (Z = 11). (the graph shows F having an Orbital Energy of 692.45, Ne+ with 47.74, and Na++ with 33.52) a. How many electrons does ...
January 31, 2015

chemistry
2C2H2(g) + 5O2(g)→4CO2(g) + 2H2O(g) a. Determine the enthalpy change for the reaction. ΔH = (4(-393.5)+ 2(-241.8)) – (2(227) + 5(0)) The enthalpy change is -2511.6. b. Determine the entropy change for the reaction. ΔS = (4(213.7)+ 2(188.7)) – (2(200.9...
January 31, 2015

Chemistry
q3=mass*specificeheat*100=2.75kg*4.19kJ/kgC*100= you do it.But it is not your answer, by 1000 I don't understand what you are saying. I put 2.75kg*4.19kJ/kgC*100 into a calculator and got 1150.6
January 31, 2015

Chemistry
I also made an error in this part of the question b. A 2.75 kg block of ice is heated until it completely melts. It is then heated again until it completely changes to water vapor. Is more energy required to melt the ice or to vaporize the liquid water? Show your calculations...
January 31, 2015

Chemistry
Answer the following questions about energy changes associated with heating and cooling a substance. Use the quantities in the table for your calculations. (table) Specific heat of water /4.184J/g*K dealta H vap for water /40.7 kJ/mol dealta H fus for water /6.02 kJ/mol dealta...
January 31, 2015

chemistry
The figure shows a cube of air at pressure 1.0 atm above a hot surface on Earth. Contact with the hot surface causes the volume of the air to expand from 2.00 × 105 L to 2.20 × 105 L by the transfer of 8.2 × 106 J of heat. Assume the systems are isolated from...
January 31, 2015

Chemistry
I am having some chemistry problems. 3. The graph compares the 1s orbital energies for the F atom (Z = 9), the Ne+ ion (Z = 10), and the Na++ ion (Z = 11). (the graph shows F having an Orbital Energy of 692.45, Ne+ with 47.74, and Na++ with 33.52) a. How many electrons does ...
January 29, 2015

Chemistry
A 2.75 kg block of ice is heated until it completely melts. It is then heated again until it completely changes to water vapor. Is more energy required to melt the ice or to vaporize the liquid water.
January 29, 2015

Chemistry
The reason I didn't say what I think Is because I originally went with planetary orbital but got it wrong. I have no idea what the right answer is.
January 28, 2015

Chemistry
How can the atomic orbital be described in the quantum mechanical wave model of the orbitals? A. A collection of balloons B. A circular ring C. A probability density
January 28, 2015

chemistry
Core electrons shield what from the pull of the nucleus? A. Valence electrons B. Neutrons C. Protons I think the answer is a
January 28, 2015

Chemistry
Which of the following elements can be detected by XPS? A. Hydrogen and lithium B. Boron and helium C. Lithium and boron I think the answer is c.
January 28, 2015

chemistry
So the answer is b.
January 28, 2015

chemistry
Nuclear magnetic resonance spectroscopy can be used to study which type of atoms? A. 16O B. 1H C. 2He
January 28, 2015

Chemistry
So the answer is a? I was originally guessing that.
January 28, 2015

Chemistry
Which of the following are excited in ultraviolet photoelectron spectroscopy? A. Valence electrons B. Core electrons C. X-rays
January 28, 2015

chemistry
How is a spectrum obtained in NMR spectroscopy? A. Low-frequency radio waves bombard the atom and cause nuclei in a low spin state to move to a higher spin state. B. High-frequency ultraviolet rays bombard the atom and cause nuclei in a high spin state to move to a lower spin ...
January 28, 2015

chemistry
3. One problem the researchers faced was an uncertainty about whether the signals observed in certain mass spectrometry data were, in fact, due to lead isotopes. Explain why this was a problem. In other words, why wasn't information about the mass of the isotopes ...
January 25, 2015

Chemistry
3. Is determining the excess reactant and limiting reactant an important part of a synthesis reaction? Is it an important part of a decomposition reaction? Explain.
January 25, 2015

chemistry
Suppose you designed an experiment in which you burned a known quantity of magnesium in air. You used the product to determine how many moles of oxygen would react with the known number of moles of magnesium. Why would burning magnesium in air cause a source of error for this ...
January 25, 2015

Chemistry
What is the form in which phosphorus exists in plant food and what ion could you use to precipitate the phosphorus.
January 23, 2015

chemistry
Use this article to answer questions about mass spectrometry and how it was used to identify lead isotopes in the air around Mexico City. Determination of Particulate Lead Using Aerosol Mass Spectrometry: MILAGRO/MCMA-2006 Observations (Ok I read the article and I just can'...
January 18, 2015

Chemistry
1. Why can’t gravimetric analysis be used to determine the concentration of sodium nitrate (NaNO) in a solution? 2. Why is it important in gravimetric analysis to add an excess amount of precipitating ions to a solution containing an analyte? 3. Relate gravimetric ...
January 17, 2015

chemistry
A. What is the standard potential, in volts, of a galvanic cell made of Ce4+ and Cu2+, given the standard reduction potentials below? Ce4+ + e− → Ce3+ Eº = 1.61 V Cu2+ + 2e− → Cu(s) Eº = 0.34 V I think it is 1.27 V but it might be 1.95V b. How...
January 17, 2015

chemistry
Suppose that an endpoint is reacted when 30 moles of KMnO4 was added. How many moles of Fe^2+ was there originally. I thought the answer was 150 moles.
January 17, 2015

chemistry
Identify the Oxidation and reduction half reaction in 2 KMNO4 + 10 FeSO4 + 8 H2SO4 -> K2SO4 + 2 MNSO4 + 5 Fe2(SO4)3 + 8 H2O Write net ionic equation
January 17, 2015

English
*Dickinson looking timidly too fearful to look up at this man questioning her about her seclusion* Please reword this for me.
January 16, 2015

Chemistry
write 2-3 sentences describing and identifying the type of chemical reaction that occurs when Fe^2+ reacts with potassium permanganate and specifying the type of solution required for the reaction to occur I don't know what type of reaction this is or what other solution ...
January 16, 2015

chemistry
identify the type of reaction that occurs between potassium carbonate and nitric acid
January 16, 2015

Chemistry
I don't understand. You said to divided answer A by 0.25 but in part b we removed the access copper.
January 6, 2015

Chemistry
This is a longer assignment. I want you to confirm my first two answers and help me figure out the last. 3 Cu (s) + 8 HNO3 (aq) → 3 Cu(NO3)2 (aq) + 2 NO (g) + 4 H2O (l) A copper penny with a mass of 3.067 g is dissolved in 100.0 ml of 1.000 M nitric acid. A. How many ...
January 6, 2015

history Civil War
How might one challenge the idea that the United States was wiser after the Civil War?
December 17, 2014

chemistry
Which of the following elements can be detected by XPS? A. Hydrogen and lithium B. Boron and helium C. Lithium and boron
December 17, 2014

Chemistry
Nuclear magnetic resonance spectroscopy can be used to study which type of atoms? A. 16O B. 1H C. 2He
December 17, 2014

chemistry
Which of the following are excited in ultraviolet photoelectron spectroscopy? A. Valence electrons B. Core electrons C. X-rays
December 17, 2014

Chemistry
Brass is commonly used to make musical instruments because it is easily malleable and has excellent acoustic properties. It consists of many copper atoms, with some replaced with zinc. What type of alloy is this? A. Brazing B. Substitutional C. Interstitial D. Iron
December 16, 2014

Chemistry
A. Ionic solid B. Molecular solid C. Covalent solid D. Graphic solid Which of this solids is soluble in water, conductive in solution, brittle and could have a melting point of 2800 C. I think the answer is A.
December 16, 2014

Chemistry
Which of the following affects how strongly anions and cations are attracted to each other in a solid? A. The nucleus B. Empty valence orbitals C. Distance between anions and cations D. Neutrons I the answer b.
December 16, 2014

chemistry
I so sorry, it took until know for me to understand what an antenna. I never had to spell it so I didn't know its spelling. After looking at this the answer is A. Right?
December 16, 2014

chemistry
The oscillation of electrons in an antenna is an example of which type of radiation/waves/rays? A. Radio waves B. Infrared rays C. Microwaves D. VLF radiation I don't understand what is being asked so I don't have a clue on the answer.
December 16, 2014

Chemistry
Why are metals malleable? A. Because they reflect incoming photons B. Because they are made of atoms that have tightly held electrons C. Because of their structure and uniform bonding in all directions D. Because their lattice energy is very high I think the answer is c but I ...
December 16, 2014

Chemistry
Which of the following is not true about molecular orbital theory? A. The bonding molecular orbital is filled before the antibonding orbital. B. Each molecular orbital can accommodate only one electron. C. The number of molecular orbitals formed is often equal to the number of...
December 16, 2014

Chemistry
The oscillation of electrons in an antenna is an example of which type of radiation/waves/rays? A. Radio waves B. Infrared rays C. Microwaves D. VLF radiation
December 16, 2014

chemistry
Which of the following spectroscopies is/are suitable for studying materials on surfaces? A. IR and UV/V B. UV/V C. NMR D. XPS and UPS
December 15, 2014

Chemistry
Which of the following is an example of sp3d2 hybridization? A. C2H6 B. IF7 C. PCl5 D. SF6
December 15, 2014

chemistry
Which statement best describes what must occur for two atoms to combine to form a chemical bond? A. The electrons of one nucleus must transfer to the nucleus of the second atom for a chemical bond to form. B. The repulsive forces of both nuclei must overcome their attractive ...
December 15, 2014

Chemistry
What is an ionic solid? A. One positive ion and one negative ion bonded to form a solid B. Many nonmetal atoms bonded together to form a solid C. Many positive and negative ions bonded to form a solid D. Many metal atoms bonded together to form a solid I believe the answer is ...
December 15, 2014

chemistry
In the Bohr model, which is the lowest energy state available for an electron? A. nth B. excited state C. first state D. ground state Im thinking the answer is c or d.
December 15, 2014

Chemistry
Which electron would have the highest ionization energy for an oxygen atom? A. 2nd B. 1st C. 5th D. 6th If it is the highest I was guessing b or d.
December 15, 2014

chemistry
A. Orbital shape B. Orientation in the orbital C. Main energy level D. Electron spin
December 15, 2014

chemistry
What is an ionic solid? A. One positive ion and one negative ion bonded to form a solid B. Many nonmetal atoms bonded together to form a solid C. Many positive and negative ions bonded to form a solid D. Many metal atoms bonded together to form a solid I believe the answer is ...
December 15, 2014

chemistry
For an atom of sulfur, which electron would require the least amount of energy to remove from the atom? A. 3s2 B. 1s1 C. 3p1 D. 3p4 I think the answer is c or d, preferring d. What would you go with?
December 15, 2014

Chemistry
I submitted the question and the correct answer was b. Thank you so much for helping me. I think the concept is just whole number. SInce you can't have a half of a student the answer was b.
December 14, 2014

Chemistry
Which of the following is an example of quantization? A. The amount of time spent in a classroom B. The number of students in a classroom C. Learning happening in a classroom D. The temperature range in a classroom I know I asked this question but I would this paragraph. Is it...
December 14, 2014

chemistry
Which of the following is an example of quantization? A. The amount of time spent in a classroom B. The number of students in a classroom C. Learning happening in a classroom D. The temperature range in a classroom I strongly believe the answer is A. Any objections.
December 14, 2014

Algebra
Marie, a resident of Metropolis, pays Metropolis an annual tax of $46 plus 2.4% of her annual income. If Marie paid $1,558 in tax, what was Marie's income?
December 12, 2014

Pages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | Next>>

Members