1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
valkas [14]
3 years ago
7

The labels on a shipment of the five chemicals A –E below were washed off by accident when the delivery truck went through a tru

ckwash with the doors open. A clever student took infrared spectra of each of the resulting unknowns. Unknown #1 had a strong, broad IR absorption at 3400–3600 cm–1, and no absorptions between 1600 and 2900 cm–1. Unknown #2 had a strong absorption at 1680 cm–1 and no absorptions above 3100 cm–1. What are the structures of unknowns 1 and 2?
Mathematics
1 answer:
Tanya [424]3 years ago
8 0

Answer:

Unknown 1: -OH group at 3400-3600

Unknown 2: Ketone and alkene group

Step-by-step explanation:

Unknown 1:

This compound has a strong IR absorption at 3400 - 3600cm-¹; this indicates that it is an alcoholic group (OH)

No absorption between 1600 and 2900cm-¹: this rule out the presence of ketone (C = O)

Hence the unknown compound is OH group

Unknown 2:

This has strong IR absorption at 1680cm-¹: this indicates the presence of (C=O) group.

No absorptions above 3100cm-¹: this indicates the presence of C = C - H

So therefore, unknown 2 is most likely to be Ketone and alkene group

You might be interested in
PLEASE HELP NEED THIS DONE.
Mandarinka [93]
A.40,48 is the right answer
7 0
3 years ago
Read 2 more answers
In a particular class, exams are worth 50% of the overall grade, quizzes are worth 30% of the overall grade, homework is worth 1
Paha777 [63]

Answer:

The student's overall grade is 85.79%

Step-by-step explanation:

Given in the question that:

Exam = 50%; Quiz = 30%, Home work = 15% and Class participation = 5%

The total giving us 100%.

A particular student scored the following;

87.9% on exams, 77.8% quiz, 90% Home work and 100%  on class participation

Calculating the percentages the student had for each;

Exam total = 50*0.879 = 43.95% earned

Quiz = 30*0.778 = 23.34% earned

Home work = 15*0.9 = 13.5% earned

Class participation = 5*1 = 5% earned

Total earned = 43.95+ 23.34 + 13.5+ 5 = 85.79%

3 0
3 years ago
a boat can travel 30 miles upstream in the same amount of time you can travel 50 miles Downstream. If the speed of the current i
almond37 [142]
Speed, S = Distance (d) / Time (t) => S= d/t => t= d/S

Let the speed of boat in still water be x mph

Resulting speed upstream = x-4 mph for a distance of 30 miles
Resulting speed downstream = x-4 mph for a distance of 50 miles

Time taken in both distances is equal.
Therefore,

30/(x-4) = 50/(x+4) => 30(x+4) = 50(x-4) => 30x+120 = 50x-200 => 120+200 = (50-30)x => 20x = 320 => x=320/20 = 16 mph

The speed of boat in still water is 16 mph.


7 0
3 years ago
Read 2 more answers
Round each number to the underlined place. <br> 4.6666<br> The third 6 is underlined
Nadya [2.5K]
Hello There!

It would be 4.667.

Hope This Helps You!
Good Luck :)
3 0
3 years ago
PLEASE HELP I DO NOT UNDERSTAND AT ALL ITS PRECALC PLEASE SERIOUS ANSWERS
Elina [12.6K]

You want to end up with A\sin(\omega t+\phi). Expand this using the angle sum identity for sine:

A\sin(\omega t+\phi)=A\sin(\omega t)\cos\phi+A\cos(\omega t)\sin\phi

We want this to line up with 2\sin(4\pi t)+5\cos(4\pi t). Right away, we know \omega=4\pi.

We also need to have

\begin{cases}A\cos\phi=2\\A\sin\phi=5\end{cases}

Recall that \sin^2x+\cos^2x=1 for all x; this means

(A\cos\phi)^2+(A\sin\phi)^2=2^2+5^2\implies A^2=29\implies A=\sqrt{29}

Then

\begin{cases}\cos\phi=\frac2{\sqrt{29}}\\\sin\phi=\frac5{\sqrt{29}}\end{cases}\implies\tan\phi=\dfrac{\sin\phi}{\cos\phi}=\dfrac52\implies\phi=\tan^{-1}\left(\dfrac52\right)

So we end up with

2\sin(4\pi t)+5\cos(4\pi t)=\sqrt{29}\sin\left(4\pi t+\tan^{-1}\left(\dfrac52\right)\right)

8 0
2 years ago
Read 2 more answers
Other questions:
  • Continue the number pattern/sequence:
    12·1 answer
  • What is 3X-6&gt;8 how do we solve this
    12·1 answer
  • Please help with this question(it’s attached)! Urgent help! I will reward brainliest to the best/first answer. Thanks in advance
    5·1 answer
  • Alx+b) = 4x + 10
    10·1 answer
  • Which function has a lower minimum value?
    14·1 answer
  • you have a 5-inch by 7-inch picture that you framed. When you hung the picture, you found that the entire area is 69.56 in. What
    13·2 answers
  • This Question: 4 pts
    13·1 answer
  • Simplify. Assume that no denominator is equal to zero. (show work) <br> help please!!!!!
    13·1 answer
  • 8- (0.75+2). Plzzz explain it
    5·1 answer
  • Consider quadrilateral FGHJ and its image F'G'H'J'. The dilation is a(n)Immersive Reader
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!