Chemical Quantities

Question 1

Relative Atomic Mass

Answer 1

The weighted average mass of all an element’s isotopes compared with one-twelfth the mass of one atom of carbon 12.

Question 2

Relative Atomic Mass Formula

Answer 2

A= weighted average mass/1 amu

Question 3

1 amu

Answer 3

1/12 * the mass of one atom of carbon 12

Question 4

Mole

Answer 4

a unit of measure containing 6.02 * 10^23 particles

Question 5

(not really a quantity) the volume of a sphere

Answer 5

4/3 πr^3

Question 6

Concentration

Answer 6

the amount of solute in a solution

Question 7

Concentrated Solutions

Answer 7

contains a large amount of solute compared to the amount of solvent present.
-concentrated solutions may be known as strong solutions

Question 8

Dilute Solutions

Answer 8

contains a small amount of solute compared to the amount of solvent present
-dilute solutions may be known as weak solutions

Question 9

Percent Composition by Mass

Answer 9

the mass of the solute divided by the mass of the solution, multiplied by 100

Question 10

If you mix two solutions of the same substances at equal volumes, the concentration is the ______ of the two starting concentrations

Answer 10

average

Question 11

Molarity

Answer 11

the number of moles of solute per liter of solution

Question 12

saturation

Answer 12

the point at which additional solute can no longer be dissolved into a solvent

Question 13

Supersaturated solution

Answer 13

a solution that holds more dissolved solute than it can normally hold at a given temperature

• contains more dissolved solute than a saturated solution
• often forms by cooling a saturated solution
• NOT STABLE

Question 14

Polar Solvents

Answer 14

solvents made up of molecules with an uneven distribution of electrons, creating a negative and positive side
-polar solutes dissolve in polar solvents

Question 15

Nonpolar solvents

Answer 15

solvents made of molecules with an even distribution of electrons. the charges on the molecules are neutralized. -nonpolar solutes dissolve in nonpolar solvents

Question 16

Freezing Point Depression

Answer 16

solutions freeze at lower temperatures than the pure solvent

Question 17

Boiling Point Elevation

Answer 17

solutions boil at higher temperatures than the pure solvent

-important at high elevations

Question 18

Osmotic Pressure

Answer 18

certain membranes allow a solvent to pass through but not the solute. when these membranes are used to separate a solution and a solvent, more solvent flows into the side containing the solution. eventually, the solution’s weight builds up enough pressure to stop the flow.