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Zumdahl - Chemical Principles 6/e (Homework)

James Finch

Chemistry - College, section 1, Fall 2010

Instructor: Dr. Friendly

Current Score: 2/33

Due: Saturday, April 2, 2011 07:00 EDT

About this Assignment

Question
Points
1 2 3 4 5 6 7
0/3 0/6 0/14 2/4 0/3 0/2 0/1
Total
2/33

Description

Chemical Principles 6th Edition by Steven Zumdahl includes more than 1570 end-of-chapter problems plus ChemWork assignments and Thinkwell® lecture videos. Questions provide links to Practice It exercises, Watch It videos, relevant textbook pages, and online, live help.

Questions 1-6 are end-of-chapter problems enhanced with links to Read It, Watch It, Practice It, and Chat About It buttons.

Read It - Relevant textbook pages

Watch It - Watch Its include 5 to 7 minute mini-lectures from Thinkwell®.

Practice It - Practice Its include Visual Exercises that combine molecular-level animations and videos demonstrations that cover core chemistry concepts. Each animation or video is accompanied by questions to aid students in conceptualization of the topic.

Chat About It - Online, live help

Question 7 is a ChemWork assignment. ChemWork assignments test students' understanding of core concepts from each chapter. If a student can solve a particular problem with no assistance, he/she can proceed directly to the answer and receive congratulations. However, if a student needs help, assistance is available through a series of hints. The procedure for assisting the student is modeled after the way an instructor would help a student with a homework problem in his or her office. The hints are usually in the form of interactive questions that guide the student through the problem solving process. Students cannot receive the right answer from the system, rather it encourages them to continue working on the problem through this system of multiple hints. ChemWork is chemically and numerically parametrized so that each student in the course receives a unique set of problems.


Instructions

This demo assignment allows many submissions and allows you to try another version of the same question for practice.



1. 0/3 points All Submissions Notes Question: ZumChemP6 3.E.031.
Question part
Points
Submissions
1 2 3
0/1 0/1 0/1
1/50 1/50 1/50
Total
0/3
 
What amount (moles) is represented by each of these samples?
(a) 21.3 mg caffeine, C8H10N4O2
WebAssign will check your answer for the correct number of significant figures.
Enter a number with the correct number of significant figures.
Your answer is incorrect. mol

(b) 2.57 1021 molecules of ethanol, C2H5OH
WebAssign will check your answer for the correct number of significant figures.
Enter a number with the correct number of significant figures.
Your answer is incorrect. mol

(c) 1.82 g of dry ice, CO2
WebAssign will check your answer for the correct number of significant figures.
Enter a number with the correct number of significant figures.
Your answer is incorrect. mol

Need Help? Read It Watch It


2. –/6 points Notes Question: ZumChemP6 3.E.035.
Question part
Points
Submissions
1 2 3 4 5 6
0/1 0/1 0/1 0/1 0/1 0/1
0/50 0/50 0/50 0/50 0/50 0/50
Total
0/6
 
Chloral hydrate (C2H3Cl3O2) is a drug formerly used as a sedative and hypnotic. It is the compound used to make "Mickey Finns" in detective stories.
(a) Calculate the molar mass of chloral hydrate.
Enter a number.


(b) How many moles of C2H3Cl3O2 molecules are in 500.1 g chloral hydrate?
Enter a number.


(c) What is the mass in grams of 1.4 10-2 mol chloral hydrate?
Enter a number.


(d) How many chlorine atoms are in 3.9 g chloral hydrate?
Enter a number.


(e) What mass of chloral hydrate would contain 3.0 g Cl?
Enter a number.


(f) What is the mass of exactly 501 molecules of chloral hydrate?
Enter a number.

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3. –/14 points Notes Question: ZumChemP6 3.E.039.
Question part
Points
Submissions
1 2 3 4
0/11 0/1 0/1 0/1
0/50 0/50 0/50 0/50
Total
0/14
 
There are several important compounds that contain only nitrogen and oxygen. Calculate the mass percent of nitrogen in each of the following.
(a) NO, a gas formed by the reaction of N2 and O2 in internal combustion engines.
Enter a number.
%

(b) NO2, a brown gas mainly responsible for the brownish color of photochemical smog.
Enter a number.
%

(c) N2O4, a colorless liquid used as a fuel in space shuttles.
Enter a number.
%

(d) N2O, a colorless gas used as an anesthetic by dentists (known as laughing gas).
Enter a number.
%

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4. 2/4 points All Submissions Notes Question: ZumChemP6 3.E.044.
Question part
Points
Submissions
1 2 3 4
1 0/1 0/1 1
3/50 3/50 5/50 3/50
Total
2/4
 
Give the empirical formula for each of these compounds. (Type your answer using the format H2O for H2.)
(a)
Answer is case sensitive.
Your answer is correct.
(b)
Answer is case sensitive.
Your answer is incorrect.
(c)
Answer is case sensitive.
Your answer is incorrect.
(d)
Answer is case sensitive.
Your answer is correct.

Need Help? Read It Watch It


5. –/3 points Notes Question: ZumChemP6 3.E.059.
Question part
Points
Submissions
1 2 3
0/1 0/1 0/1
0/50 0/50 0/50
Total
0/3
 
Over the years, the thermite reaction has been used for welding railroad rails, in incendiary bombs, and to ignite solid-fuel rocket motors. The reaction is given below.

Fe2O3(s) + 2 Al(s) → 2 Fe(l) + Al2O3(s)

What masses of iron(III) oxide and aluminum must be used to produce 18.0 g iron?
aluminum
WebAssign will check your answer for the correct number of significant figures.
Enter a number with the correct number of significant figures.
 g
iron(III) oxide
WebAssign will check your answer for the correct number of significant figures.
Enter a number with the correct number of significant figures.
 g
What is the maximum mass of aluminum oxide that could be produced?
WebAssign will check your answer for the correct number of significant figures.
Enter a number with the correct number of significant figures.
 g

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6. –/2 points Notes Question: ZumChemP6 3.E.071.
Question part
Points
Submissions
1 2
0/1 0/1
0/50 0/50
Total
0/2
 
Hydrogen cyanide is produced industrially from the reaction of gaseous ammonia, oxygen, and methane, as shown below.

2 NH3(g) + 3 O2(g) + 2 CH4(g) → 2 HCN(g) + 6 H2O(g)

If 6.14 103 kg each of NH3, O2, and CH4 are reacted, what mass of HCN and of H2O will be produced, assuming 100% yield?
HCN
WebAssign will check your answer for the correct number of significant figures.
Enter a number with the correct number of significant figures.
 g
H2O
WebAssign will check your answer for the correct number of significant figures.
Enter a number with the correct number of significant figures.
 g

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7. –/1 points Notes Question: ZumChemP6 3.CW.14.
Question part
Points
Submissions
1
0/1
0/50
Total
0/1
 


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