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
mihalych1998 [28]
2 years ago
15

1. A sample of polystyrene is found to have a number-average molar mass of 89,440 g mol−1 . Neglecting contributions from end gr

oups, calculate the number-average degree of polymerization of this sample. Assuming that the sample has a molar mass dispersity of 1.5, calculate its weight-average molar mass.
Chemistry
1 answer:
Snowcat [4.5K]2 years ago
8 0

Answer:

The weight-average molar mass of polystyrene is 134,160 g/mol.

Explanation:

Molar mass of the monomer styrene , C_8H_8, M=104 g/mol

Given , number average molar mass of the polymer , M'= 89,440 g/mol

Degree of polymerization = n

n=\frac{M'}{M}=\frac{89,440 g/mol}{104 g/mol}=860

The weight-average molar mass = M_{avg}=?

Molar mass dispersity is ratio of weight-average molar mass to the number average molar mass of the polymer.

\text{Molar mass dispersity}=\frac{M_{avg}}{M'}

1.5=\frac{M_{avg}}{89,440 g/mol}

M_{avg}=89,440 g/mol\times 1.5 = 134,160 g/mol

The weight-average molar mass of polystyrene is 134,160 g/mol.

You might be interested in
The pressure on a sample of gas is increased from 1.0 atm to 3.0 atm. If the new volume is 0.52 L, find the original volume.
swat32

Answer: 1.56 ATM

Explanation: if we assume temperature is constant, gas obeys

Boyles law pV= constant. Then p1·V1= p2·V2. And V1 = p2V2/p1

= 3.0 atm·0,52 l / 1.0 atm

3 0
3 years ago
the half of an oxidation-reduction reaction shows the iron gains. what does this electron gain mean for iron.
Nataly [62]

The correct answer is option C, that is, it is reduced.

In reduction and oxidation reactions, reduction refers to the loss of an oxygen atom from a molecule or the gaining of one or more electrons. A reduction reaction is observed from the perspective of the molecule being reduced, as when one molecule gets reduced, another one gets oxidized. The complete reaction is called a redox reaction.

In the given case, iron gains electrons mean that it is reduced.  


3 0
2 years ago
What is the limiting reactant when 19.9 g CuO react with 2.02 g H2?
Harlamova29_29 [7]

Answer:

Explanation:

use the equation

moles = mass/mr

=19.9/79.5

=0.250moles of CuO

then do the same for

H = 2.02/1

=2.02

so CuO is the limiting reagent because there is less amount of it.

Hope this helps  :)

4 0
2 years ago
At what temperature does ice start to melt
Delicious77 [7]

Answer:

Explanation:

The answer is 32°F or 0° Celsius.

Hope it helped you.

5 0
2 years ago
How many days the average menstrual cycle lastas
ICE Princess25 [194]
A cycle is counted from the first day of 1 period to the first day of the next period. The average menstrual cycle is 28 days<span> long. Cycles can range anywhere from </span>21<span> to </span>35 days<span> in adults and from </span>21<span> to </span>45 days<span> in young teens.</span>
5 0
3 years ago
Other questions:
  • true or false einsteins equation implies that a large amount of mass can be converted into a small amount of energy
    15·2 answers
  • Due to the fact that ionic compounds have strong intermolecular forces they are __________ at room temperature.
    6·1 answer
  • Round to 4 significant figures 4,567,986
    7·2 answers
  • Is celery organic chemically? If so, what is it (carbohydrate, protein, etc)?
    10·1 answer
  • Substance X has a fixed volume, and the attraction between its particles is strong. Substance Y has widely spread out particles
    15·2 answers
  • Can someone help me to answer the questions 8 and 9
    13·1 answer
  • How does transcription work
    10·1 answer
  • Which chemical equation best represents the Law of Conservation of
    9·1 answer
  • Soft of easy help plz<br><br><br><br> B<br><br> C<br><br> A<br><br> D
    14·1 answer
  • what volume will it occupied 40 degrees celsius a gas sample was collected when a temperature is 27 degrees celsius and the volu
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!