Chemistry Chapter 5: Phases, Gases and Solutions

Question 1

Why would HF have a small effect on the boiling point of water compared to HI, HCl and HBr

Answer 1

The boiling point of a solution depends on the number of particles of solute present in solution.

Hydrochloric acid hydrobromic acid hydroidic acid are strong acids

HF is weak and doesn’t completely dissociate

When each acid breaks down, it dissociates into 2 moles of ions per mole of solute dissolved particles from HF

Therefore, there are fewer fewer dissolved HF ions in solution compared to strong acids like HCl, HBr, and HI.

Question 2

A colligative property is a property that is dependent on the

Answer 2

ratio of solute to solvent concentration, but not the identity of the solute (or the solvent).

Question 3

How does polarity, molecular weight affect osmosis

Answer 3

Polarity and molecular weight don’t affect osmosis

Question 4

Supersaturation

Answer 4

a state where a solution contains more of the dissolved material than could be dissolved by the solvent under normal circumstances. If a supersaturated system is perturbed, the excess solute will crystallize (i.e. precipitate) out of solution and onto the glass rod

Question 5

At STP, one mole of an ideal gas occupies a volume

Answer 5

22.4L

Question 6

Charles Law

Answer 6

Question 7

Boyles Law

Answer 7

Question 8

Avogardo’s Law

Answer 8

Question 9

Combined Law

Answer 9

Question 10

If the total pressure for the products of this reaction is 1.2torr, how do you find the partial pressure of H2O?

Answer 10

1) find total number of mols of products (in this case there are 3 mols)

2) find proportion of species in question (in this case 2 H2O mols out of 3 total mols)

3) (2/3)*1.2 = 0.8 torr pH2O

Question 11

If you see a thermal expansion coefficient given in a table, check if they are asking about volume change—

Answer 11

Make sure to multiply by 3!!!

Question 12

Henry’s Law

Answer 12

Henry’s law, statement that the weight of a gas dissolved by a liquid is proportional to the pressure of the gas upon the liquid

Question 13

High osmolarity means what?

Answer 13

High concentration of solutes. Therefore, answer is B because the body is trying to converse water. the urine is highly concentrated, meaning very salty because water is being retained

Question 14

osmolarity vs concentration

Answer 14

Summary: Osmolarity measures the total number of osmotically active particles per liter of solution, while concentration measures the moles of solute per liter, differing when solutes dissociate.

Example: A 1 M NaCl solution has an osmolarity of 2 Osm/L because NaCl dissociates into Na⁺ and Cl⁻ ions.