Calculate the valency of the element?

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Discussion Overview

The discussion revolves around calculating the valency of an element based on its equivalent weight and vapour density. Participants explore the definitions and implications of vapour density in relation to molecular weight and equivalent weight, with a focus on the necessary units for calculations.

Discussion Character

  • Homework-related
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant states that the equivalent weight of the element is 4 and its chloride has a vapour density of 59.25, prompting a request for how to proceed with the calculation.
  • Several participants question the meaning of "VD," with suggestions that it could refer to either vapour density or venereal disease.
  • Another participant confirms that "VD" refers to vapour density and emphasizes the need for units to perform calculations.
  • There is a discussion about the units of vapour density, with one participant noting that the author of their reference book does not specify units, despite vapour density being defined as molecular weight divided by 2.
  • A participant explains that vapour density is a ratio and does not have units, similar to relative molecular mass, while also mentioning the modified definition involving molecular weight.
  • One participant points out that vapour density is numerically equal to half the molar mass and suggests considering the relationship between equivalent weight and molar weight, while also mentioning the term 'equivalence factor' as an alternative to valency.

Areas of Agreement / Disagreement

Participants express uncertainty regarding the definition of vapour density and its units, leading to multiple interpretations. There is no consensus on how to proceed with the calculation or the terminology to use.

Contextual Notes

Participants highlight the lack of clarity regarding the units of vapour density and the relationship between equivalent weight and molar weight, which remains unresolved.

avistein
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1.The equivalent weight of an element is 4.It's chloride has a V.D.=59.25.Find out the valency of the element


Homework Equations





3.Molecular wt=108.50 u.Then how to proceed?
 
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What is VD?
 
Borek said:
What is VD?

Venereal Disease? :devil:
 
Borek said:
What is VD?

I think VD is Vapour Density.

Mark44 said:
Venereal Disease?

:-p
 
Pranav-Arora said:
I think VD is Vapour Density.

Slightly more likely than Mark's suggestion :wink:, but if so, we will need units to be able to calculate anything.
 
@Borek and all others,V.D is Vapour Density.
 
@Borek,what units do you need?
 
Units of vapour density - is it in stones per cubic mile, or pounds per barrell, or something else? Without units number you listed doesn't make any sense.
 
Borek said:
Units of vapour density - is it in stones per cubic mile, or pounds per barrell, or something else? Without units number you listed doesn't make any sense.

:smile:

At least in the book I follow, the author has never mentioned the units of vapour density even though it is defined as Molecular weight/2.
 
  • #10
Pranav-Arora said:
:smile:

At least in the book I follow, the author has never mentioned the units of vapour density even though it is defined as Molecular weight/2.

See the original definition of Vapour Density. Its just the ratio of density of substance with respect to hydrogen, or ratio of mass of substance to the mass of same volume of hydrogen under same condition of temperature and pressure. Ratio does not have any unit, just like the relative molecular mass. Note: I used "substance" word. Better replace it with "given gas".

When you apply laws of gases, etc.. you get the modified definition of vapour density as Molecular weight/2. That Molecular Weight is in fact Relative Molecular Weight.
 
  • #11
avistein said:
3.Molecular wt=108.50 u.Then how to proceed?

This isn't even an attempt since by definition, vapour density is numerically equal to half the molar mass.

Think what the relationship between equivalent weight and molar weight is. Also instead of valency you might want to use the term 'equivalence factor' although note that IUPAC has discouraged the use of equivalence concept.
 

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