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Physics question

I need help with this question please. I thought of using the formula to find specific latent heat but I'm not sure. Can you please help or advise me?

Substance “X” has a molar mass of 0.98 kg mol-1 and each molecule in the liquid state has 6 nearest neighbours. Given that the binding energy, ε0, of a pair of molecules is 2×10-20 J, calculate the latent heat of vaporisation (in kJ kg-1) for this substance.

Thankyou
Original post by ahmed2017
I need help with this question please. I thought of using the formula to find specific latent heat but I'm not sure. Can you please help or advise me?

Substance “X” has a molar mass of 0.98 kg mol-1 and each molecule in the liquid state has 6 nearest neighbours. Given that the binding energy, ε0, of a pair of molecules is 2×10-20 J, calculate the latent heat of vaporisation (in kJ kg-1) for this substance.

Thankyou

You can find the number of molecules in 1 kg of X.
Since 0.98 kg is 1 mol of X, this means
NA molecules of X are found in 0.98 kg.

Then use the information given to work out the latent heat of vaporisation
Reply 2
Avatar for ahmed2017
ahmed2017
OP
10
Original post by BobbJo
You can find the number of molecules in 1 kg of X.
Since 0.98 kg is 1 mol of X, this means
NA molecules of X are found in 0.98 kg.

Then use the information given to work out the latent heat of vaporisation


to find the number of molecules, do I multiply mole by avogadros constant. And then find the number of molecules for 1 kg?
(edited 5 years ago)
Original post by ahmed2017
to find the number of molecules, do I multiply mole by avogadros constant. And then find the number of molecules for 1 kg?

Since molar mass is 0.98 kg mol^-1, you can find number of moles in 1 kg. Then multiply by Avogadro's constant and you have number of molecules

you can also do 1 mol -> 0.98 kg
therefore 0.98 kg -> 6.02 x 10^23
hence 1kg ...
Reply 4
Avatar for ahmed2017
ahmed2017
OP
10
[QUOTE="BobbJo;80888220"]Since molar mass is 0.98 kg mol^-1, you can find number of moles in 1 kg. Then multiply by Avogadro's constant and you have number of molecules

you can also do 1 mol -> 0.98 kg
therefore 0.98 kg -> 6.02 x 10^23
hence 1kg Y
Original post by BobbJo
Since molar mass is 0.98 kg mol^-1, you can find number of moles in 1 kg. Then multiply by Avogadro's constant and you have number of molecules

you can also do 1 mol -> 0.98 kg
therefore 0.98 kg -> 6.02 x 10^23
hence 1kg ...


Yes, that's what I did. Thank you so much

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