Chemistry- Solutions

Question 1

solution

Answer 1

• homogenous mixture composed of 2 or more substances
• small particles (atoms, ions, or molecules)
• will NOT separate on standing

Question 2

solute

Answer 2

• material that is dissolved

- often a solid

Question 3

solvent

Answer 3

• the material doing the dissolving

- often a liquid

Question 4

soluble

Answer 4

• able to dissolve in the solvent

- in order for substances to be soluble, they must have the same polarity

Question 5

insoluble

Answer 5

unable to dissolve in the solvent

Question 6

polar

Answer 6

• unequal charge distribution
• central atom often has unshared electron pairs
• not very symmetrical
• dipole dipole or hydrogen bonds

Question 7

nonpolar

Answer 7

• equal charge distribution
• central atom often has no unshared electron pairs
• highly symmetrical
• van der waal forces

Question 8

suspension

Answer 8

• contain large solute particles that will settle unless constantly stirred
• ex. sand in water

Question 9

colloid

Answer 9

• formed when particles are larger than those in a solution but smaller than a suspension
• ex. butter, smoke, whipping cream

Question 10

tyndall effect

Answer 10

• the scattering of light by small particles

- COLLOIDS exhibit the tyndall effect

Question 11

electrolyte

Answer 11

• substance that dissolves in water to form a solution that conducts electricity
• often an ionic compound (tend to be solid)
• ex. NaCl

Question 12

non-electrolyte

Answer 12

• substance that dissolves in water to form a solution that does not conduct an electric current
• ex. sugar

Question 13

surface area

Answer 13

• the greater the surface area, the quicker the rate of dissolving
• more solute molecules in contact with the solvent

Question 14

agitating a solution

Answer 14

• helps to disperse the solute particles

- brings fresh solvent in contact with the solute

Question 15

heating the solvent

Answer 15

• increasing temp. increases collisions between solute and solvent
• also increases energy of collisions

Question 16

solution equilibrium

Answer 16

physical state in which the opposing processes of dissolution and crystallization of a solute occur at equal rates

Question 17

unsaturated

Answer 17

• solution that contains less solute than a saturated solution under existing conditions
• no dissolved solute remains

Question 18

saturated

Answer 18

• solution that contains the maximum amount of dissolved solute
• solute will fall to bottom if amount of solute > solubility
• exists at equilibrium

Question 19

supersaturated

Answer 19

• solvent is holding more solute than it should be

- adding more solute causes the excess solute to crash out of the solution

Question 20

solubility

Answer 20

the amount of the substance required to form a saturated solution with a specific amount of solvent at a specific temp.

Question 21

pressure

Answer 21

• affects GAS not solid
• as pressure increases (molecules are closer together) the solubility of the gas will increase
• directly proportional

Question 22

temperature

Answer 22

• as temp. increases, the solubility of gas will decrease (farther apart)
• solubility of a solid increases

Question 23

concentration

Answer 23

measure of the amount of solute in a given amount of solvent or solution

Question 24

molarity

Answer 24

number of moles of solute in one liter of solution

Question 25

molarity formula

Answer 25

moles of solute / liters of solution

Question 26

volumetric flask

Answer 26

- very precise | - used to prepare a solution and dilution

Question 27

molality

Answer 27

concentration of a solution expressed in moles of solute per kilogram of solvent

Question 28

molality formula

Answer 28

moles of solute / kilograms of solvent

Question 29

percent concentration by mass

Answer 29

- (mass of solute / mass of solution) * 100 | - mass of solution = mass of solute + mass of solvent

Question 30

percent concentration by volume

Answer 30

- (volume of solute / volume of solution) * 100 | - volume of solution is NOT the sum of the volumes of solute and solvent

Question 31

parts per million (ppm)

Answer 31

- used for very low concentrationns | - (mass of solute / mass of solution) * 1,000,000

Question 32

mole fraction

Answer 32

- moles of A / total moles | - most useful when working with gases

Question 33

stock solution

Answer 33

solution with high concentration that needs to be diluted

Question 34

formula for dilution

Answer 34

- M1V1 = M2V2 - M is MOLARITY - keep stock on one side and diluted solution on the other

Question 35

colligative properties

Answer 35

- properties that depend on the concentration of solute particles NOT their identities - concentration will be in terms of MOLALITY

Question 36

nonvolatile solute

Answer 36

will not become a gas and dissolve

Question 37

vapor pressure _____ when nonvolatile solute is added

Answer 37

- decreases - solvent molecules are more spread out - solute will also be in contact with the air

Question 38

freezing point _____ when nonvolatile solute is added

Answer 38

- decreases - entropy is greater, temperature must be lower to organize it - solute does NOT freeze with the solvent

Question 39

boiling point _____ when nonvolatile solute is added

Answer 39

- increases | - more bonds have to be broken

Question 40

freezing point depression formula

Answer 40

- Kfmi | - Kf for water: -1.86 C/m

Question 41

van't hoff factor

Answer 41

- the i in freezing/ boiling formula | - number of particles produced by the solute

Question 42

boiling point elevation formula

Answer 42

- Kbmi - Kb for water: 0.51 C/m - MUST ADD 100 C to get the new boiling point