Question

For each solute, identify the better solvent: water or carbon tetrachloride.

Answer 1

I2, CH2O, KF, C6H6

Answer 2

Which of those molecules are non-polar?
Which are polar?

Water is a polar solvent
Carbon tetrachloride is a non-polar solvent

Answer 3

Like dissolves like

Answer 4

Do you just have to memorize which are polar and nonpolar or is there a way to tell?

Answer 5

No it is just logic, do you know what electronegativity is?

Answer 6

As a rule of thumb ionic compounds dissociate better in polar solutions.

Answer 7

i know what electronegativity is

Answer 8

When two or more atoms are covalently bonded to each other electrons will tend to stay closer to the more electronegative compound this results in the molecule having polarity

When atoms like carbon and hydrogen are bonded which carbon and hydrogen have very similar electronegativity electrons are shared equally so electrons hang out around the carbon and hydrogen about equally.

Same goes for two of the same atoms that are covalently bonded to eachother since they have the same electronegativity electrons are going to hang out around both atoms equally.

A compound like FCH3 is going to be polar electrons are going to hang out around the flourine atom more in the molecule resulting in the carbon and hydrogen having a partial positive charge and the flourine having a partial negative charge. This is because flourine is much more electronegtive then hydrogen or carbon.

Look up electronegativity trend in the periodic table or just trends in the periodic table in a search engine to see what atoms are more electronegative etc

Answer 9

Sorry for not being very clear half asleep here

Answer 10

essentially non-polar is an equal electron sharing between atoms in a molecule
Polar molecules are unequal electron sharing between atoms in a molecule

Answer 11

Another thing that might be too advanced for what you are doing is that if a molecule is symmetric it is normally non-polar

It may help to look at electron density diagrams to understand what I mean,
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTjfj8W1mvVKs1QI8_Dbumm5EEcDazdje_uPkJCncMISsIfz99igw

Answer 12

Symmetric molecules can also be non-polar that you would think would be polar but I doubt you will be tested on such a thing

Answer 13

Look at HF diagram, Red means higher electron density lighter colour means lower electron density. HF has a partial positive charge near H and a partial negative charge near F

Answer 14

because the electrons are hanging around the more electronegative flourine

Answer 15

Follow?

Answer 16

Electronegativity is a pretty important concept to understand, as it can help you understand the chemistry of molecules and how they will react at least in regards to organic chemistry

Answer 17

Check this site out, these are some important concepts to know

http://chemwiki.ucdavis.edu/Inorganic_Chemistry/Descriptive_Chemistry/Periodic_Trends_of_Elemental_Properties/Periodic_Trends

Answer 18

Thank you so much for all your help