January 22, 2021, 10:40:20 AM
Forum Rules: Read This Before Posting

0 Members and 1 Guest are viewing this topic.

#### tekki

• New Member
• Posts: 4
• Mole Snacks: +0/-0
##### Question about calculating the molecular weight
« on: November 22, 2020, 09:07:08 PM »
Hi! Today I was doing my homework and I stuck on one exercise. I have to calculate the molecular weight of polypropylene, where n=320. Can someone help me and show me how can I calculate it? Here's the picture to this exercise.

I hope that someone can show me it! It'd mean the world to me!

EDIT: this is my attempt:

mC=12
mH=1
n=320

12*3+1*6=42u

42*320=13440

Answer: the molecular weight of polypropylene equals 13440
« Last Edit: November 22, 2020, 09:32:50 PM by tekki »

#### Babcock_Hall

• Chemist
• Sr. Member
• Posts: 4478
• Mole Snacks: +272/-19
##### Re: Question about calculating the molecular weight
« Reply #1 on: November 22, 2020, 09:26:01 PM »

#### tekki

• New Member
• Posts: 4
• Mole Snacks: +0/-0
##### Re: Question about calculating the molecular weight
« Reply #2 on: November 22, 2020, 09:30:16 PM »
oh, okay, so gimme a few second and I will post this here!

#### tekki

• New Member
• Posts: 4
• Mole Snacks: +0/-0
##### Re: Question about calculating the molecular weight
« Reply #3 on: November 22, 2020, 09:33:19 PM »

I updated my post

#### Borek

• Mr. pH
• Deity Member
• Posts: 26247
• Mole Snacks: +1706/-402
• Gender:
• I am known to be occasionally wrong.
##### Re: Question about calculating the molecular weight
« Reply #4 on: November 23, 2020, 03:34:46 AM »
Very close, but technically incorrect.

ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info, pH-meter.info

#### tekki

• New Member
• Posts: 4
• Mole Snacks: +0/-0
##### Re: Question about calculating the molecular weight
« Reply #5 on: November 23, 2020, 03:36:22 AM »
Is it gon' be 13440u? Or you meant something else?

• Mr. pH