# Pages CH217 - Home CH217 - Homework

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## Homework Assignment 1: General Chemistry Review (due 2/12/2008)

1. Get a General Chemistry text that you may use as a reference for the semester.
2. Complete the attached CH141 and CH142 exams (you may consult each other, but must submit your own work).  Please turn in a hard copy in class.
Ch142 Final 2000.pdf           CH141 Final Exam 2003.pdf

## Homework Assignment 2: Room Energy Audit (due 2/19/2008)

Every student will help prepare a Colby student energy audit of electrical appliances used by the student body.  Start by claiming an appliance by adding your name to the table below.  You may fill in the rest of your row at a later date.

Name

Appliance

Energy Consumption (J/year)

Number on Campus

Total Energy

Sharon Fuller

microwave

5.91 * 10^7 kJ/year

1077.1

6.37 * 10^7 kJ

Katie Billington

Printer

Mengfei Zhang

desk lamp

Sasha Bartels

mini fridge

Brittany Tschaen

Television

Dan Heinrich

Stereo/Speakers

Li Yu Chan

cell phone & charger

13.6 * 10^3 kJ

1555.8

2.12 * 10^7 kJ

Brian DiMento

Christmas lights

1.69 * 10^8 J/year

568

9.60 * 10^10 J

Rob Dillon

PS2

Mischa Noll

iPod

Katie Harris

Blow Dryer

3.97E5 kJ

1023.1

4.06E8 kJ

Kristina Shiroka

Fan

Elissa Teasdale

Computer/Laptop

Julia Coffin

Alarm clock

Lane Mahoney

DVD player

Cat Zweig

Coffee Maker

Jason Hine

Hair Straightener

Brynna Patel

N64

total

Once you have selected the appliance, survey 10 or more rooms to get a statistical sampling of the appliance frequency on campus.  Determine the energy consumed by the appliance over the course of the academic year and compute the total energy consumed by all students using the appliance.  Put your data in the table above and provide the details on your appliance and your calculations below.  This assignment is only submitted on this page.

Post answers to assignment 1 below:  (list name, appliance, and then details)

Steve Jobs, Apple laptop computer

Details on the calculations for computer energy consumption ....

_______________________________________________________________________________________________

Li Yu Chan, Cell phone charger

 Sample Brand Voltage (V) Amperes (A) 1 Motorola 5.00 0.85 2 Sony Ericsson 4.90 0.45 3 Black Berry 5.00 0.75 4 Nokia 5.70 0.80 5 Motorola 5.10 0.80 6 Nokia 5.30 0.50 7 Unbranded 5.00 0.60 8 Sony Ericsson 4.90 0.45 9 Samsung 5.00 0.70 10 Motorola 5.00 0.85 Average - 5.09 0.68

Average Power = 5.09 * 0.68 = 3.46 W
[DWK: Watch your order of operations in the average power calculation. The average power is not the same as the average voltage x average amps. However in this case it will be close]

Average energy consumption per year, assuming 3 hours daily use = 3.46 J/sec *60 sec/min * 60 min/hr * 3 hr/ day * 365 days = 13.6 *10^3 kJ

Total Energy based on probability that 10/12 students have cell phone chargers = (13.6*10^6) * 10/12* 1867 = 2.12*10^7 kJ

___________________________________________________________________________________________________________________

Katie Harris, Blow Dryer

 Brand Voltage (V) Current (A) Power (W) 1 Jilbere 125 10 1250 2 Physique 125 15 1875 3 Revlon 125 15 1875 4 Conair 125 15 1875 5 Perfection Classic 125 15 1875 6 Vidal Sassoon 125 15 1875 7 Conair 125 15 1875 8 Conair 125 15 1875 9 Conair 125 15 1875 10 Conair 125 15 1875 Average 1812.5

Average Energy Consuption a year assuming 10 minutes daily use.

1812.5 J/sec * 60 sec/min * 10 min/day * 365 day/year = 3.97E8 J

Assuming every female (54.8%) on campus and no males use a blow dryer

3.97E8 J * 1867 * 54.8% = 4.06E11 J = 4.06E8 kJ

___________________________________________________________________________

Sharon Fuller, microwave

120V * 7.5A = 900W

Average energy consumption per year assuming 3 minutes daily use:

900 J/sec * 60 sec/min * 3 min/day * 365 day/year = 5.91 * 10^7 J = 5.91 * 10^4 kJ

With 15 microwaves per 26 students in survey:

5.91 x 10^4 kJ * 1867 students * (15/26) = 6.47 * 10^7 kJ

_____________________________________________________________________________

Brian DiMento, Christmas Lights

120V * 0.34A = 40.8W

Energy consumption assuming 5 hours of daily use, over an academic year (approximately 230 days on campus):

40.8 J/sec * 60 sec/min * 60 min/hr * 5 hr/day * 230 day/year = 1.69 * 10^8 J/year

Survey: 7 100 bulb strands found per 23 students.

1.69 * 10^8 J * 1867 students * (7/23) =  9.60 * 10^10 J total

## Homework Assignment 3:  The Hybrid Car (due 2/21/2008)

Using the US DOE Hybrid vehicle cost calculator, compare the lifetime cost of running a hybrid vehicle versus a conventional vehicle of the same size.   Each group of four students should select a different vehicle size class.   Use current fuel prices, a 10 year vehicle lifetime, and an annual millage of 15,000 miles.   Thy hybrid vehicles will save gasoline and, therefore, reduce carbon dioxide emissions.  How much would it cost to purchase carbon credits to offset the increased gasoline consumption of a conventional powered car?  How would purchasing carbon credits change the economics of running a hybrid versus a conventional car?  Please show your work and provide details on your calculations.

Group Assignments for this assignment:

Group I
Hine, Jason F.
Chan, Li Yu
DiMento, Brian P.
Shiroka, Kristina A.
Group II
Zhang, Mengfei
Noll, Michael S.
Fuller, Sharon R.
Group III
Dillon, Robert W.
Billington, Kaitlyn E.
Bartels, Sarah E.
Patel, Brynna M.
Group IV
Teasdale, Elissa L.
Zweig, Catherine E.
Melese, Mesay
Harris, Katie
Group V
Tschaen, Brittany A.
Mahoney, Lane J.
Heinrich, Daniel G.
Coffin, Julia P.

Post answers to assignment 2 below:  (list names of group members at the beginning of each question).
Your answer should be in narrative form with links to external data sources and specifics on any calculations.  Each student in the group should contribute to the answer. This assignment is only submitted on this page.

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