Ch 12 Section 3 Flashcards Preview

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Flashcards in Ch 12 Section 3 Deck (22):
1

the concentration of a solution is a measure of the amount of solute in a

given amount of solvent or solution

2

two different ways of expressing the concentrations of solutions:

molarity and molality

3

sometimes, solutions are referred to as... or ... but these aren't definite terms

dilute; concentrated

4

dilute means that there is a relatively small amount of

solute in a solvent

5

concentrated means that there is a relatively large amount of

solute in a solvent

6

the terms dilute and concentrated are unrelated to the degree to which a solution is

saturated

7

a saturated solution of a substance that is not very soluble might be very

dilute

8

molarity is the number of moles of solute in

one liter of solution

9

to relate the molarity of a solution to the mass of solute present, you must know the

molar mass of the solute

10

the relationship between molarity, moles, and volume is expressed as:

molarity (M)= amount of solute (mol)/ volume of solution (L)

11

the molarity of any solution can be calculated by dividing the number of moles of solute by the

number of liters of solution

12

a 1 M solution is not made by adding 1 mol of solute to

1 L of solvent

13

Instead, 1 mol of solute is first dissolved in less than

1 L of solvent

14

then, the resulting solution is carefully diluted with more solvent to bring the

total volume to 1 L

15

Molality is the concentration of a solution expressed in moles of solute per

kilogram of solvent

16

a solution that contains 1 mol of solute dissolved in exactly 1 kg of solvent is a

"one molal" solution

17

the symbol for molality is an italicized

m

18

molality=

moles solute/ mass of solvent (kg)

19

the molality of any solution can be found by dividing the number of moles of solute by the

mass in kg of the solvent in which it is dissolved

20

note that if the amount of solvent is expressed in grams, the mass of solvent must be converted to kilograms by multiplying by this conversion factor:

1 kg/ 1000 g

21

concentrations are expressed as molalities when studying properties of solutions related to

vapor pressure and temperature changes

22

molality is used because it does not change with changes in

temperature