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Author Topic: How to get atoms of something having % of mass?  (Read 3924 times)

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IBM

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How to get atoms of something having % of mass?
« on: August 10, 2018, 03:06:27 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.
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sjb

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Re: How to get atoms of something having % of mass?
« Reply #1 on: August 10, 2018, 09:25:09 PM »

If you have, for instance 100g of oxide, what mass is M, and what mass is O? How many moles of each?
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IBM

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Re: How to get atoms of something having % of mass?
« Reply #2 on: August 10, 2018, 11:51:56 PM »

O is 16g and M is (100-16) = 84g. 16g O = 1 mole.
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sjb

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Re: How to get atoms of something having % of mass?
« Reply #3 on: August 11, 2018, 01:03:02 AM »

What do the percentages you have quoted mean?
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IBM

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Re: How to get atoms of something having % of mass?
« Reply #4 on: August 11, 2018, 03:27:44 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
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sjb

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Re: How to get atoms of something having % of mass?
« Reply #5 on: August 11, 2018, 03:50:15 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?
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IBM

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Re: How to get atoms of something having % of mass?
« Reply #6 on: August 11, 2018, 02:43:40 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 
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sjb

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Re: How to get atoms of something having % of mass?
« Reply #7 on: August 11, 2018, 09:26:44 PM »

In the word MO, what is the ratio of the letters M to O?

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IBM

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Re: How to get atoms of something having % of mass?
« Reply #8 on: August 11, 2018, 10:58:32 PM »

M:O = 1:3 or 13 : 15
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sjb

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Re: How to get atoms of something having % of mass?
« Reply #9 on: August 11, 2018, 11:15:20 PM »

I'm not sure where you get these figures from - care to explain a little more?
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IBM

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Re: How to get atoms of something having % of mass?
« Reply #10 on: August 12, 2018, 02:08:22 PM »

In the word MO, what is the ratio of the letters M to O?


Could you simplify your point, please?
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sjb

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Re: How to get atoms of something having % of mass?
« Reply #11 on: August 12, 2018, 07:41:04 PM »

If you have 1 mole of a compound MO, how many moles of M and how many moles of O do you have?
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IBM

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Re: How to get atoms of something having % of mass?
« Reply #12 on: August 13, 2018, 04:49:04 AM »

1 mole of M and 1 mole of O present
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sjb

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Re: How to get atoms of something having % of mass?
« Reply #13 on: August 13, 2018, 07:30:26 AM »

So in a sample of MO with 1.725 mole of O, how much M is there?
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IBM

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Re: How to get atoms of something having % of mass?
« Reply #14 on: August 13, 2018, 08:05:42 PM »

in 100g MO, M = (100 - 27.6) = 72.4g
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