Major Ideas: Solutions

Question 0

What happens when a solid dissolves?

Answer 0

Particles break away from the solid lattice and mix with the solvent molecules

Question 1

What is a solution?

Answer 1

Homogenous mixture made from a solute dissolving in a solvent

Question 2

Rule for predicting solubilities

Answer 2

Like dissolves like

Question 3

Will a molecule containing H-bonds dissolve in water? Why?

Answer 3

Yes

- new bonds formed between solute and water are also H-bonds

Question 4

Name 3 things that happen during the formation of a solution regrading the rearrangement of bonds

Answer 4

• bonds between particles in solid(solute) are broken
• bonds between liquid particles are distrusted as SOLUTE particles move between them
• new bonds are formed between solute particles and liquid particles

Question 5

Name the major factor in determining whether a solution forms

Answer 5

Relatives strengths of bonds that need to be broken and new bonds being formed

Question 6

Will a non-polar molecule with only dispersion forces dissolve in water?
- why?

Answer 6

No
- hydrogen bonds need to be broken between solvent (water) molecules but only dispersion forces can form between solvent and solute

Question 7

Will non-polar solutes dissolve in non-polar solvents?

- why?

Answer 7

Yes
- bonds broken between solute and solvent molecules are dispersion forces and the new bonds will hence also be dispersion forces

Question 8

For polar organic molecules (e.g alcohols):

• what happens to solubility in WATER when the hydrocarbon chain increases?
• what happens to the solubility in a NON-POLAR solvents as the number of polar functional groups in the hydrocarbon increase?

Answer 8

• decrease

- decrease

Question 9

What happens to the solubility of a polar solute and ionic compound when the POLARITY of the solvent decreases?

Answer 9

• the solubility decreases for both

Question 10

What happens to the solubility of a non-polar solute when the polarity of the solvent decreases?

Answer 10

• increases

Question 11

What are ion-dipole forces and how are they formed?

Answer 11

Forces that hold molecules to ions

- ionic solid dissolves in water and then POLAR water molecules are attracted to the positive and negative ions

Question 12

What are complex ions?

Answer 12

Ions with water molecules attracted to them

Question 13

What is one mole?

Answer 13

Amount of substance that contains 6.022x10^23 particles of that substance

Question 14

What is a concentration?

Answer 14

Quantity of solute dissolved in a particular quantity of solution

Question 15

What/how can concentration be expressed in parts per million (ppm)

Answer 15

Mass in mg of solute dissolved in 1kg of solution
- ppm= mass of solute (mg)
__________________
Mass of sln (kg)

Question 16

Equation for % composition

Answer 16

Mass of solute (g)
__________________ x100
Mass of solution (g)