IES Final Exam

 

This exam is due on Monday, December 9th at 9 a.m.

 

Be sure to SHOW YOUR WORK!!!!!!  Please put your name on every page and be thorough.

 

The purpose of this exam is for you to get an indication of how well you understand the material studied this quarter.  This is an open-book, open notes exam—you may use any written resources you find helpful.  What you hand in should represent only your individual work and we take your signature to be your assurance that you did not work with anyone or discuss this exam with anyone.  You may ask questions only of the instructors. 

 

I have neither given nor received aid in this exam.

 

            Signature           _________________________

 

            Name                _________________________

 

 

1)    A) Draw the Lewis structure for N2H2.

 

 

 

 

 

B) Draw the shape of the N2H2 molecule using VSEPR theory and state the molecular and electronic shapes of N2H2.

 

 

 

 

 

 

 

 

 

2)    Balance the equation:

Al   +     Cl2   à    Al2Cl6

 

 

3)    Balance the equation:

K2CO3   +    Al2Cl6    à     Al2(CO3)3   +    KCl

 

 

 

4)    What is the mass of 1 mole of gold atoms?

 

5)    Calculate the molecular weight of penicillin, C16H26O4N2S

 

 

 

 

6)    How many grams of nitrogen are there in 5.4 moles of N2O? 

 

 

 

 

 

7)    How many hydrogen atoms are there in 4.2 moles of (NH4)2SO4?

 

 

 

 

 

 

 

8)    Which weighs more:  0.082 moles of H2O or 3.01 x 1021 molecules of H2SO4? 

 

 

 

 

 

 

 

 

 

 

 

9)    A power plant emits 1.0 x 106 g of sulfuric acid, H2SO4, an hour.  How many grams of calcium hydroxide, Ca(OH)2 does it have to use to neutralize all of the sulfuric acid? 

UNBALANCED equation:  H2SO4  +   Ca(OH)2  à   H2O   +   CaSO4 

 

 

 

 

 

 

 

 

 

 

 

10) A) Diesel fuel is a mixture of many hydrocarbons.  For simplicity, we will assume that its chemical formula is C15H32.  Write a balanced equation for the combustion of diesel fuel, C15H32. 

 

 

 

 

 

B) If 1 gal of diesel fuel is burned, how many pounds of carbon dioxide are produced?  You will need this number below.  Assume that the density of C15H32 is 0.80g/mL.

 

 

 

 

 

 

 

 

 

 

 

 

C)   Now you’ll do a calculation to compare the CO2 emissions from transporting fruits and vegetables to a local farmers market vs. mass production where perishables typically travel about 1500 miles.  First calculate the yearly CO2 emissions for a person who buys all of her fruits and vegetables from a local farmer’s market (look only at CO2 emissions from transport to market, you can ignore CO2 emissions from production).  Assume that local farmers use a pickup truck and travel an average of 50 miles to market. 

 

Useful information for C) and D)

Average U.S. fruit and vegetable consumption/person/year: 710 lbs/person/year

Pickup truck: 15 mpg gasoline

Pick-up truck capacity: 1 ton = 2000 lbs.

Trailer: 5 mpg diesel  (assume C15H32)

Trailer capacity: 40,000 lbs.

The combustion of 1 gallon of gasoline emits approximately 18 pounds of CO2

The combustion of 1 gallon of diesel emits ??(see your calculation from B) ? lb of CO2

 

 

 

 

 

 

 

 

D)   Now calculate the yearly CO2 emissions for a person who buys all of her fruits and vegetables from a supermarket that gets its produce from an average of 1500 miles away.  Assume that the produce is transported by semi-trailers powered by diesel.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

E)    Compare your answers to C) and D).  What did you learn?

 

 

 

 

 

 

11) Describe how global warming would impact the ozone hole. Give specifics!

 

 

 

 

 

 

12) Continue your drawing of the C cycle.

__List the sources and sinks of C-containing GHG (CO2 and CH4)

__Draw the C cycle including the sources and sinks

__Indicate relative amounts of stocks (with respect to the other stocks by the size of the

    boxes) and flows (by the width of the arrows).

__Identify photosynthesis and respiration.  

__Quantify the flows.

__Designate arrows in red as positive feedback loops, and in green as negative loops. 

Check that you have done each of these items.  Attach your C-cycle drawing to the back of the exam.

 

What have you learned from this exercise? (write this here)

 

 

 

 

 

 

 

 

 

 

 

 

13) We have focussed much on methane in understanding agriculture’s contribution to climate change.  Why?  Be specific.  Under what environmental conditions is methane formed? Give examples.

 

 

 

 

 

 

 

 

 

 

 

 

b)Why is methane production more problematic for global warming than carbon dioxide production? 

 

 

 

 

 

c) Two ways of reducing GHG in the atmosphere are to reduce their emissions or to

 increase their sequestering.   How can methane emissions be reduced?

 

 

 

 

 

 

 

 

d) What alternative technology produces methane as an energy source?  As methane is used, how does the greenhouse gas potential change?  What is the balanced equation for this process? 

 

 

 

 

 

 

 

 

 

 

 

14) A number of studies have shown that organic agriculture emits less GHG than conventional, high agrochemical input agriculture.  Why is this is so?  There is more than one reason.  Be specific.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

15) How might a switch to biofuel (methanol made from distilled corn) decrease global warming?  Increase it?  How might biofuel be produced in order to decrease global warming?

 

 

 

 

 

 

 

 

 

 

16) What is a carbon offset project?  Draw it.  Why are they controversial? (give several reasons)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

17)  How do human alterations in the N cycle contribute to global warming? (give several ways)