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Topic: What is the approximate molecular weight of liquid?  (Read 364 times)

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Offline Win,odd Dhamnekar

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What is the approximate molecular weight of liquid?
« on: November 19, 2020, 08:46:19 AM »
 How to answer this question?

Any science consists of the following process.
 1) See2)Hear 3) Smell if needed4) Taste if needed
5) Think 6) Understand 7) Inference 8) take decision [Believe or disbelieve, useful or useless, healthy or unhealthy, cause or effect, favorable or unfavorable, practical or theoretical, practically possible or practically impossible or any other required criteria]

Offline AWK

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Re: What is the approximate molecular weight of liquid?
« Reply #1 on: November 19, 2020, 09:02:12 AM »
You have all the information you need to calculate the molar mass from the ideal gas law.
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Offline Win,odd Dhamnekar

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Re: What is the approximate molecular weight of liquid?
« Reply #2 on: November 21, 2020, 10:17:36 AM »
Hello,
      Weight of the unknown liquid inside the bulb after completion of reaction is 50.1879 grams - 50.0230 grams =0.1649 grams.

Volume of the water= 102.7535 grams - 50.0230 grams = 52.7305 grams = volume of the vapour of liquid after its immersion in oil bath at 423.15 K( 150° C) and 0.980 bar.

Using ideal gas law equation PV=nRT, [itex]\frac{0.980 bar*0.0527305 liters}{0.0831447 bar*liters/(mol*K)*423.15 K}=0.001468787 mol [/itex]

Molar  weight of the unknown liquid =0.1649 grams/0.001468787 mol= 112.269 grams/mol. Its molecular weight is 1.86427e-22 u.

 
« Last Edit: November 21, 2020, 12:01:49 PM by Win,odd Dhamnekar »
Any science consists of the following process.
 1) See2)Hear 3) Smell if needed4) Taste if needed
5) Think 6) Understand 7) Inference 8) take decision [Believe or disbelieve, useful or useless, healthy or unhealthy, cause or effect, favorable or unfavorable, practical or theoretical, practically possible or practically impossible or any other required criteria]

Offline AWK

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Re: What is the approximate molecular weight of liquid?
« Reply #3 on: November 21, 2020, 12:51:26 PM »
The approximate molecular weight - 112.
AWK

Offline Win,odd Dhamnekar

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Re: What is the approximate molecular weight of liquid?
« Reply #4 on: November 21, 2020, 02:31:49 PM »
Definitions of molecular mass, molecular weight, molar mass and molar weight

Molecular mass (molecular weight) is the mass of one molecule of a substance and is expressed in the unified atomic mass units (u). (1 u is equal to 1/12 the mass of one atom of carbon-12)

Molar mass (molar weight) is the mass of one mole of a substance and is expressed in g/mol
Any science consists of the following process.
 1) See2)Hear 3) Smell if needed4) Taste if needed
5) Think 6) Understand 7) Inference 8) take decision [Believe or disbelieve, useful or useless, healthy or unhealthy, cause or effect, favorable or unfavorable, practical or theoretical, practically possible or practically impossible or any other required criteria]

Offline mjc123

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Re: What is the approximate molecular weight of liquid?
« Reply #5 on: November 21, 2020, 03:00:05 PM »
Quote
Molar  weight of the unknown liquid =0.1649 grams/0.001468787 mol= 112.269 grams/mol. Its molecular weight is 1.86427e-22 u.
No. You have divided the molar mass by NA, which gives you the molecular weight in g. What is the molecular weight in u?

Offline Win,odd Dhamnekar

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Re: What is the approximate molecular weight of liquid?
« Reply #6 on: November 21, 2020, 10:38:11 PM »
 Oh! You are correct. AWK's answer is correct. Thanks for pointing out my mistake.   The molecular weight in u 1s 112.168
Any science consists of the following process.
 1) See2)Hear 3) Smell if needed4) Taste if needed
5) Think 6) Understand 7) Inference 8) take decision [Believe or disbelieve, useful or useless, healthy or unhealthy, cause or effect, favorable or unfavorable, practical or theoretical, practically possible or practically impossible or any other required criteria]

Offline mjc123

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Re: What is the approximate molecular weight of liquid?
« Reply #7 on: November 22, 2020, 06:22:35 AM »
Remember: The molecular weight in u is numerically equal to the molar mass in g/mol. (This follows from the definitions.)

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