November 27, 2024, 05:48:46 PM
Forum Rules: Read This Before Posting


« previous next »
Pages: [1] 2 3   Go Down

Topic: How to get atoms of something having % of mass?  (Read 11513 times)

0 Members and 1 Guest are viewing this topic.

Offline IBM

  • Regular Member
  • ***
  • Posts: 81
  • Mole Snacks: +0/-7
How to get atoms of something having % of mass?
« on: August 10, 2018, 09:06:27 PM »
Two oxides of a metal contain 27.6% and 30% of oxygen respectively. If the formula of the first oxide is MO, find that of the second?
Now my problem is how to find the atoms of O from the masses of 27.6% and 30.0 %?
How to get atoms of something having % of mass? I am confused.
Logged

Offline sjb

  • Global Moderator
  • Sr. Member
  • ***
  • Posts: 3653
  • Mole Snacks: +222/-42
  • Gender: Male
Re: How to get atoms of something having % of mass?
« Reply #1 on: August 11, 2018, 03:25:09 AM »
If you have, for instance 100g of oxide, what mass is M, and what mass is O? How many moles of each?
Logged

Offline IBM

  • Regular Member
  • ***
  • Posts: 81
  • Mole Snacks: +0/-7
Re: How to get atoms of something having % of mass?
« Reply #2 on: August 11, 2018, 05:51:56 AM »
O is 16g and M is (100-16) = 84g. 16g O = 1 mole.
Logged

Offline sjb

  • Global Moderator
  • Sr. Member
  • ***
  • Posts: 3653
  • Mole Snacks: +222/-42
  • Gender: Male
Re: How to get atoms of something having % of mass?
« Reply #3 on: August 11, 2018, 07:03:02 AM »
What do the percentages you have quoted mean?
Logged

Offline IBM

  • Regular Member
  • ***
  • Posts: 81
  • Mole Snacks: +0/-7
Re: How to get atoms of something having % of mass?
« Reply #4 on: August 11, 2018, 09:27:44 AM »
In the first MO, if the total amount is 100g, then O is 27.6g similarly,
in the second MO, if the total amount is 100g, then O is 30g respectively
Logged

Offline sjb

  • Global Moderator
  • Sr. Member
  • ***
  • Posts: 3653
  • Mole Snacks: +222/-42
  • Gender: Male
Re: How to get atoms of something having % of mass?
« Reply #5 on: August 11, 2018, 09:50:15 AM »
How many moles of O is 27.6g? In the example of MO, what is the mass of M left and how many moles of it are there?
Logged

Offline IBM

  • Regular Member
  • ***
  • Posts: 81
  • Mole Snacks: +0/-7
Re: How to get atoms of something having % of mass?
« Reply #6 on: August 11, 2018, 08:43:40 PM »
1.725 mole of O is 27.6g.
in the MO, 72.4g of M left.
But my question is how to calculate the mole of M? because I don't know the molar mass of M 
Logged

Offline sjb

  • Global Moderator
  • Sr. Member
  • ***
  • Posts: 3653
  • Mole Snacks: +222/-42
  • Gender: Male
Re: How to get atoms of something having % of mass?
« Reply #7 on: August 12, 2018, 03:26:44 AM »
In the word MO, what is the ratio of the letters M to O?

Logged

Offline IBM

  • Regular Member
  • ***
  • Posts: 81
  • Mole Snacks: +0/-7
Re: How to get atoms of something having % of mass?
« Reply #8 on: August 12, 2018, 04:58:32 AM »
M:O = 1:3 or 13 : 15
Logged

Offline sjb

  • Global Moderator
  • Sr. Member
  • ***
  • Posts: 3653
  • Mole Snacks: +222/-42
  • Gender: Male
Re: How to get atoms of something having % of mass?
« Reply #9 on: August 12, 2018, 05:15:20 AM »
I'm not sure where you get these figures from - care to explain a little more?
Logged

Offline IBM

  • Regular Member
  • ***
  • Posts: 81
  • Mole Snacks: +0/-7
Re: How to get atoms of something having % of mass?
« Reply #10 on: August 12, 2018, 08:08:22 PM »
Quote from: sjb on August 12, 2018, 03:26:44 AM
In the word MO, what is the ratio of the letters M to O?


Could you simplify your point, please?
Logged

Offline sjb

  • Global Moderator
  • Sr. Member
  • ***
  • Posts: 3653
  • Mole Snacks: +222/-42
  • Gender: Male
Re: How to get atoms of something having % of mass?
« Reply #11 on: August 13, 2018, 01:41:04 AM »
If you have 1 mole of a compound MO, how many moles of M and how many moles of O do you have?
Logged

Offline IBM

  • Regular Member
  • ***
  • Posts: 81
  • Mole Snacks: +0/-7
Re: How to get atoms of something having % of mass?
« Reply #12 on: August 13, 2018, 10:49:04 AM »
1 mole of M and 1 mole of O present
Logged

Offline sjb

  • Global Moderator
  • Sr. Member
  • ***
  • Posts: 3653
  • Mole Snacks: +222/-42
  • Gender: Male
Re: How to get atoms of something having % of mass?
« Reply #13 on: August 13, 2018, 01:30:26 PM »
So in a sample of MO with 1.725 mole of O, how much M is there?
Logged

Offline IBM

  • Regular Member
  • ***
  • Posts: 81
  • Mole Snacks: +0/-7
Re: How to get atoms of something having % of mass?
« Reply #14 on: August 14, 2018, 02:05:42 AM »
in 100g MO, M = (100 - 27.6) = 72.4g
Logged
Pages: [1] 2 3   Go Up
« previous next »
Sponsored Links