Question

Question

Answer 1

#1

Answer 2

#2 just one question

Answer 3

#3

Answer 4

#4

Answer 5

#160 carbon tetra chloride would definitely be the lowest, b/c it has just a polar covalent bond. I think that would be a liquid. heat of fusion (s) --> (l).

Answer 6

I think I'll go with C for that question cuz I feel that H2O must be having a high heat of fusion. H2O has H bonds so in order to break that we need greater amount of heat. But I'm not sre

Answer 7

161 I'll go with answer C

Answer 8

196 I'll go with 1st answer

Answer 9

208 I'll go with D

Answer 10

206 it is C

Answer 11

@sweetburger

Answer 12

160.
You need to consider the force of the intermolecular bond between different molecules.

we have:
CCl4 - it's a gas at room t, so it's so it's fusion temprature is much under 0C'
H20- liquid at room t, the intermolecular forces are: van der vals and h-bond. They are are weak forces, and we know that it fusion t it's' little more than 0C'
NaCl and Al2O3 are bouth salt, instad we had a inic bond, and it is much stronger than van der vals or h-bond (cuz it's the attraction between partial charges, while in ionic we have entire charge). I had no idea which had higher fusing point between two salt. But wiki told me Al2O3 (2000 C') while NaCl (800 C').

So it should be the answer A.

Answer 13

Like at first i thought hydrogen bonds was the strongest, but then it was heat of fusion i.e melting.

Answer 14

160.
i get it, Al2O3 had higher fusion t, cuz the atoms Al and O are much more eletronegative instade of Na and Cl. So following Coulombs law of the interaction between charged objects, the forse is stronger because the atoms are more charged.

Answer 15

got confused by that l\[Al _{2}O _{3}\] is ionic. so you consider charges? of ions

Answer 16

@Bozhena that formula only deals with the magnitude of charges right? how does that apply to the ionic compounds, don't you have to take into consideration r?

Answer 17

the way i understood that was that the smaller ions have greater attraction? b/c they can get closer

Answer 18

yes, i mean. We need to know which between two salt has strongest intermolecular bond (cux it's the bond you break during the fusion).
So you first need to find how much charg will had each salt.
Now you can see tha each molecule could be rappresented as

U need to employ much more energy to break the interaction of force 4 than 2

Answer 19

Question 206.

1 mol of every gas has 22.4L occupied of volume.

\[\frac{ mol }{ 22.4L } = \frac{ 2mol }{ ? }\]

44.8 mol*L = mol(x)

44.8L = Volume

Answer 20

@Bozhena I see what you did for the first part.. the aluminum has a much greater electronegativity value so it's bond is going to be stronger.

Answer 21

how does columns law apply to this if we were to use that?

Answer 22

196.

The density is 2g/L, if you assume to have a conteiner of 1L, You can find g of gas. 2g/l * 1L= 2g

You also have the mols, and you know that Molar Mass is expressed in g/mol. So 2g/1mol = 2g/mol

The molecule which have MM=2g/mol is H2

Answer 23

160.
consider that at che atomic level r does not matter, so consider r constant (i mean it does metter but the diffrence is very very small).