Aqueous solutions

Question 1

Why is H2O a good solvent

Answer 1

Because it is polar, it has partial charges due to the dipoles created by H bonding i.e Dipole-dipole intetraction.

• It stabilises high energy ions in the solution
• overcomes the attractive forces of the ionic compounds and prevents them from recombining

Question 2

Why is ice less dense?

Answer 2

Because when water freezes, the H bonds also freeze in place, and they move away from each other creating open spaces, causing it to expand and e less dense due to the open space.

Question 3

Solvation definition

Answer 3

Dissociation of ions due to hydration

Question 4

How does dissolution occur?

Answer 4

The charges of the dipoles on water attract the cations and anions of the molecules and pulls them away from each other

Question 5

Can non-polar gases dissolve in H20?

Answer 5

Yes, through the formation of temporary dipoles (when H2O comes close to electron cloud, it repels some e-s, forming a temporary positive dipole and attracts the ions towards it)

Question 6

Solubility of substances are crucial in the body for:

Answer 6

Transport of inorganic mats and gases + transport of drugs

Question 7

H20 has high surface tension and heat capacity because of?

Answer 7

H bonding, the H2O also absorbs and retains heat energy which remains for a while after due to high heat capacity

Question 8

How do ice skates work?

Answer 8

Pressure decreases the freezing point of water, so when lots of pressue applied on a thin blade, ice melts and you glide on a water molecule

Question 9

Other polar solvents

Answer 9

Alcohols, COOH, Amines, Amino acids

Question 10

What is dissolution?

Answer 10

Solute particles become surrounded by solvent ones.

Question 11

Most ionic compounds dissociate spontaneously

Answer 11

yes because of strong H bonds of H2O

Question 12

Which molecules are easier to deform

Answer 12

NPs with larger e- clouds as e-s are further away from nucleus, meaning that nucleus has a weaker hold on the e-s

Question 13

Why is Dilute H2SO4 a strong acid?

Answer 13

It completely dissociated ions in H2O, how strong is how well it dissociates

Question 14

is special about H bonding?

Answer 14

The bonds are strong but are able to be unmade (mediocre strength bonds), helps with biological interactions

Question 15

Reason for high BPs

Answer 15

The more electronegative the element, the stronger the H bond.

Question 16

How many different forms of ice?

Answer 16

14, manipulate the H bonding to change the form

Question 17

Concentration of H2O per litre at 25ºC

Answer 17

55 mol Lˆ-1

Question 18

Ice –> water

Answer 18

energy applied, in h2o, h bonds are constantly being made and broken

Question 19

How many H2O molecules around Na and Cl ions when dissociated

Answer 19

Around 5-7, h2o molecules move in and out

Question 20

Bonds of molecular compounds

Answer 20

H bonds

Question 21

Definition of strong in chem

Answer 21

To be completely dissociated in a solvent, i.e dilute H2SO4 as compared to conc. H2SO4. conc. H2SO4 has a lot of H bonding going on and it’s not completely dissociated