Chemistry

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Answer all of theses questions and it must be submitted in 2 hours please be on time 

 

 

 

Question 1 (2 points)

 Question 1 Unsaved
 
What is the density of a block of unknown material with a mass of 11.90-g if the dimensions are: 
length = 2.2 cm
height = 1.7 cm
width = 7.5 cm
 
 

Question 2 (2 points)

 Question 2 Unsaved
 
What is the density of a 16.97-g object if the dimensions of the block are:
length = 12.6 mm
height = 6.8 cm
width = 0.014 m
 
 

Question 3 (2 points)

 Question 3 Unsaved
 
What is the density of a 21.73-g irregularly shaped object if the initial volume of water was 23.4-mL and the volume rose to 56.0-mL after the object was added?
 
 

Question 4 (2 points)

 Question 4 Unsaved
 
A volume of water was delivered using a buret and experimentally determined to have a mass of 2.44-g.  What was the final volume of water on the buret if the inital was 0.17-mL? [assume the density of water is 1.00g/mL]
 
 

Question 5 (2 points)

 Question 5 Unsaved
 
Identify the following chemical using the information provided below:
initial buret reading: 1.2-mL
final buret reading: 10.5-mL
mass: 8.184-g
 


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Question 1 (2 points)

 Question 1 Unsaved
 
What is the density of a block of unknown material with a mass of 11.90-g if the dimensions are: 
length = 2.2 cm
height = 1.7 cm
width = 7.5 cm
 
 

Question 2 (2 points)

 Question 2 Unsaved
 
What is the density of a 16.97-g object if the dimensions of the block are:
length = 12.6 mm
height = 6.8 cm
width = 0.014 m
 
 

Question 3 (2 points)

 Question 3 Unsaved
 
What is the density of a 21.73-g irregularly shaped object if the initial volume of water was 23.4-mL and the volume rose to 56.0-mL after the object was added?
 
 

Question 4 (2 points)

 Question 4 Unsaved
 
A volume of water was delivered using a buret and experimentally determined to have a mass of 2.44-g.  What was the final volume of water on the buret if the inital was 0.17-mL? [assume the density of water is 1.00g/mL]
 
 

Question 5 (2 points)

 Question 5 Unsaved
 
Identify the following chemical using the information provided below:
initial buret reading: 1.2-mL
final buret reading: 10.5-mL
mass: 8.184-g
 

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Question 1 (2 points)

 Question 1 Unsaved
 
What is the name of N2O5?
 
 

Question 2 (2 points)

 Question 2 Unsaved
 
What is the name of the compound composed of Ca and P?
 
 

Question 3 (2 points)

 Question 3 Unsaved
 
What is the formula for the compound composed of calcium and phosphate?
 
 

Question 4 (2 points)

 Question 4 Unsaved
 
What is the name of the compound composed of iron and carbonate? [Hint: iron has a +3 charge in this compound]
 
 

Question 5 (2 points)

Match the following acids to the correct names: Question 5 Unsaved
 
sulfuric acid
hydrosulfuric acid
sulfurous acid
 
H2SO4
H2SO3
H2S

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Question 1 (2 points)

 Question 1 Unsaved
 
Cu+2 forms which color when dissolved in water?
 
 

Question 2 (2 points)

 Question 2 Unsaved
 
Calculate the percent recovery of copper if: 1.5-g is the initial amount and 1.2-g is the amount recovered.
[Hint: do not include the percentage sign when typing in your answer]
 
 

Question 3 (2 points)

 Question 3 Unsaved
 
Which of the following is NOT a good explination/indication as to the results obtained in the above question?
 
 

Question 4 (2 points)

 Question 4 Unsaved
 
Calculate the percent recovery of copper if: 7.6-g is the initial amount and 9.5-g is the amount recovered.
[Hint: do not include the percentage sign when typing in your answer]
 
 

Question 5 (2 points)

 Question 5 Unsaved
 
Which of the following is NOT a good explination/indication as to the results obtained in the above question?
 
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Question 1 (2 points)

 Question 1 Unsaved
 
Once acid was added to the supplement, what was the purpose of filtering the solution?
 
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Question 2 (2 points)

 Question 2 Unsaved
 
When sodium carbonate is added to the filtrate, fizzing occurs.  Which gas is being produced?
 
Question 3 (2 points)
 Question 3 Unsaved
 
What was the purpose of heating the calcium carbonate precipitate?
 
Question 4 (2 points)
 Question 4 Unsaved
 
How many milligrams of calcium is in 1.46-g of calcium carbonate?
 
Question 5 (2 points)
 Question 5 Unsaved
 
What is the percent mass of calcium in a calcium supplement if 1.34-g of calcium carbonate is extracted from a 2.80-g pill?
 
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Quiz

 
 

 

 

Question 1 (2 points)

 Question 1 Unsaved
 
How much heat is lost by 5 grams of a metal if the temperature changed from 90c to 40c? (c=3.95 J/gK)
 
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Question 2 (2 points)

 Question 2 Unsaved
 
Assume a piece of hot metal is added to a colorimeter containing 50mL of water at 22C. The amount of heat released by the metal was determined to be 1000 J, and the equilibrium temperature in the calorimeter was 26C. Remembering that the specific heat of water is 4.18 J/gC, how much heat in joiles does the clorimeter gain?
 
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Question 3 (2 points)

 Question 3 Unsaved
 
Assume the heat absorbed by the calorimeter was 200 J. What is the calorimeter constant (Heat Capacity) if the temperature changed from 22C to 26C?
 
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Question 4 (1 point)

 Question 4 Unsaved
 
Calculate the Calorimeter Constant if 25 g of water at 58C was added to 25 g of water at 25C with a resulting temperature of 35C?
 
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Question 1 (2 points)

 Question 1 Unsaved
 
What is the definition of the Enthalpy of Reaction?
 
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Question 2 (2 points)

 Question 2 Unsaved
 
Which of the following reactions needs to be reversed to solve for the Heat of Neutralization between Hydrochloric Acid and Ammonia?
 
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Question 3 (2 points)

 Question 3 Unsaved
 
What is the molar heat of neutralization (Enthalpy of Reaction) in kJ/mol if 5 moles of HA neutralized 5 moles of BOH and released 11123 J of heat?
 
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Question 4 (2 points)

 Question 4 Unsaved
 
Calculate the molar heat of neutralization in kJ/mol of the reaction between HA and BOH given the following information:
The temperature change equals 5C, 
50 mL of 1 M concentration of Acid 
50 mL of 1 M concentration of Base
Heat capacity of the calorimeter is 6.5 J/C.
Remember that the specific heat of water is 4.18 J/gC
 
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Question 5 (2 points)

 Question 5 Unsaved
 
How much heat is gained (in Joules) by the water where a chemical reaction takes place in 100 mL aqueous solution and has a temperature increase of 12 C?
 
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Question 1 (2 points)

 Question 1 Unsaved
 
What is the definition of the Enthalpy of Reaction?
 
Save
 

Question 2 (2 points)

 Question 2 Unsaved
 
Which of the following reactions needs to be reversed to solve for the Heat of Neutralization between Hydrochloric Acid and Ammonia?
 
Save
 

Question 3 (2 points)

 Question 3 Unsaved
 
What is the molar heat of neutralization (Enthalpy of Reaction) in kJ/mol if 5 moles of HA neutralized 5 moles of BOH and released 11123 J of heat?
 
Save
 

Question 4 (2 points)

 Question 4 Unsaved
 
Calculate the molar heat of neutralization in kJ/mol of the reaction between HA and BOH given the following information:
The temperature change equals 5C, 
50 mL of 1 M concentration of Acid 
50 mL of 1 M concentration of Base
Heat capacity of the calorimeter is 6.5 J/C.
Remember that the specific heat of water is 4.18 J/gC
 
Save
 

Question 5 (2 points)

 Question 5 Unsaved
 
How much heat is gained (in Joules) by the water where a chemical reaction takes place in 100 mL aqueous solution and has a temperature increase of 12 C?
 
Save
 
 
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Question 1 (2 points)

 Question 1 Unsaved
 
What is the wavelength of light (in nm) if the frequency is 6.2 x 10^14 (1/sec)?
 
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Question 2 (2 points)

 Question 2 Unsaved
 
What is the wavelength of light (in nm) if the energy of the wave is 1.87 x 10^-19 J?
 
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Question 3 (2 points)

 Question 3 Unsaved
 
What is the final concentration of a solution if 106-mL of a 3.3-M solution was diluted to 487-mL?
 
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Question 4 (2 points)

 Question 4 Unsaved
 
What is the final concentration of a solution if 15-mL of a 2.0-M solution was diluted to 100-mL and this process was repeated two more times?
 
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Question 5 (2 points)

 Question 5 Unsaved
 
 
Using the attached chart, find the concentration of a solution if the absorption was 0.27.  

 
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Question 1 (2 points)

 Question 1 Unsaved
 
How many lone pairs of electrons are there on the central atom in ammonia (NH3)?
 
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Question 2 (2 points)

 Question 2 Unsaved
 
What is the electronic geometry of PCl5?
 
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Question 3 (2 points)

 Question 3 Unsaved
 
What is the molecural geometry of NH3?
 
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Question 4 (2 points)

 Question 4 Unsaved
 
What is the orbital hybridization of the central atom S in SF4?
 
Question 5 (2 points)
 Question 5 Unsaved
 
Is S=C=O a polar molecule?
 
 
 
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A sample of gas occupies 27 L under a pressure of 1.3 atm. What would the resulting valume be if the pressure were increased to 3.9 atm if the temperature did not change?
 
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A sample of CO2 occupies 200 ml at 373 K. At what temperature (in K) would it occupy 300 ml if the pressure did not change?
 
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A sample of Helium occupies 200 L at 30ºC under a pressure of 855 torr. What is the volume it occupies at standard temprature and pressure (STP)?
 
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Nitric acid, a very important industrial chemical, is made by dissolving the gas nitrogen dioxide (NO2) in water. Calculate the moles of gas produced in 2 L volume container, 762 torr and 50 ºC if the gas behaves as ideal:
 
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An unknown amount of sodium bicarbonate reacts with excess hydrochloric acid in a gas producing reaction.  The reaction vessel has the same set-up as that in lab.  Paying attention to the partial pressures of water in your lab book, if 119-mL of salt water was collected in the beaker at 23C and 765mmHg, how many grams of sodium bicarbonate did one begin with?

 

 

 
 
 
 
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Should be submitted in less than two hours  
 



    • Posted: 4 years ago
    • Due: 
    • Budget: $45
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