To determine whether a compound is polar or nonpolar you have to take into account:
1) formation of dipoles due to the difference in electronegativities of the atoms
2) shape of the molecule to conclude whether there is a net dipole momentum.
You already, likely, know that the electronegativities of H and O are significatively different, being O more electronegative thatn H. So, you can conclude easilty that the electrons are atracted more by O than by H, thus creating two dipoles H→O
Regarding the shape, it may appear that the molecule is symmetrical, which would lead to the cancellation of the two dipoles. But that is not the true. The H2O2 is not symmetrical.
The lewis structure just show this shape
** **
H - O - O - H
** **
which is what may induce to think that the molecule is symmetrical, leading to the misconception that it is nonpolar.
But in a three dimensional arrangement you could see that the hydrogens are placed in non symmetrical positions, which leads to the formation of a net dipole momentum, and thus to a polar molecule.
The fact that H2O2 is a polar compound is the reason why it can be mixed with water and the H2O2 that you buy in the pharmacy is normally a solution in water.
So, the hydrogen peroxide is polar because the hydrogens are not placed symmetrically in the molecule, which result in a net dipole momentum.
Answer:
89,4%
Explanation:
If you have a solutio of 2,5g of acetanilide in 50mL of water and you warm this solution to 100°C you will dissolve all acetanilide because the maximum solubility in 50mL will be:
5,5g / 100mL → 2,75g / 50mL.
Then, if you cold the water to 0°C the solubility in 50mL will be:
0,53g / 100mL → 0,265g / 50mL.
That means you will precipitate:
2,5g - 0,265g = <em>2,235g of acetanilide</em>
The theoretical percent recovery will be:
2,2365g / 2,5g ×100 = <em>89,4%</em>
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I hope it helps!
Atomic mass Na = 22.99 u.m.a
22.99 g ------------------ 6.02x10²³ atoms
175 g -------------------- ?? atoms
175 x (6.02x10²³) / 22.99 => 4.58x10²⁴ atoms
hope this helps!
Answer:
Skeletal system
Explanation:
The skeletal system is made up of all the bones, cartilage, and ligaments in the body. There are over 200 bones in the human skeleton, connected by joints which allow them to bend and rotate.
It protects the vital organs, gives our body form and structure, and allows us to move (or bust a move!)
To move, the skeletal system works with the muscles and nerves in the body.
Fajans' Rules are used to predict whether a chemical bond will be covalent or ionic.
<span>This depends on: </span>
<span>- the charge on the cation </span>
<span>- the size of the cation </span>
<span>- the size of the anion </span>
