The Mole

Question 1

Avogadro’s constant

Answer 1

6.02 * 10^(23)

Question 2

Mole

Answer 2

6.02 * 10^(23) particles

Question 3

N(particles) = n(moles) x Avogadro’s constant

Answer 3

How to calculate the number of particles

Question 4

Relative atomic mass

Answer 4

the weighted average atomic mass of all the isotopes of an element. (the mass listed on the periodic table)

Question 5

Relative molecular mass

Answer 5

the sum of all the relative atomic masses of all the atoms in a molecule

Question 6

Formula unit

Answer 6

The smallest ratio between two atoms in an ionic compound based on the ion’s charges

Question 7

Hydrate

Answer 7

Ionic compounds in which water molecules form coordination bonds. (ex: CuSO4 * 5H20)

Question 8

Stoichiometric coeffiecient

Answer 8

the number written in front of atoms, ions and molecules in a chemical reaction to balance the number of each element on both the reactant and product sides of the equation.

Question 9

Molar mass

Answer 9

the mass of 1 mol of a substance. It is numerically equal to the relative molecular mass of the substance.

Question 10

n(moles) = m (mass)/ M (molar mass)

Answer 10

How to calculate moles from mass

Question 11

Molecular formula

Answer 11

the actual number of atoms of each element in that molecule.

Question 12

Empirical formula

Answer 12

the simplest ratio of atoms in the substance.

Question 13

Mole ratio

Answer 13

The ratio of elements by mol in a molecule, can be found with the empirical formula

Question 14

Percent composition

Answer 14

the elemental composition of a compound expressed in percent by mass.

Question 15

Solution

Answer 15

Homogeneous mixtures of two or more components

Question 16

Solute

Answer 16

the smaller component of a solution

Question 17

Solvent

Answer 17

the major component of a solution, properties of a solution are similar to the solvent

Question 18

Solutions in which the solvent is water

Answer 18

Aqueous solution

Question 19

contains a large ratio of solute to solvent

Answer 19

concentrated solution

Question 20

contains a small ratio of solute to solvent.

Answer 20

dilute solution

Question 21

molar concentration (c) or molarity

Answer 21

a measure of amount of solute per unit volume of solution (typically mol dm^-3)

Question 22

mass concentration (p)

Answer 22

a measure of mass of solute per unit volume of solution (typically g dm^-3)

Question 23

Stock solutions

Answer 23

chemicals stored in concentrated solutions and diluted to the required concentration when needed

Question 24

Spectrophotometry

Answer 24

an analytical technique based on the measurement of intensity of ultraviolet and near-infrared radiation. can use to determine concentration of colored substances.

Question 25

Colorimetry

Answer 25

an analytical technique based on the the measurement of intensity of visible light. can use this to determine concentration of colored substances.

Question 26

Absorbance

Answer 26

a value describing the amount of light absorbed by the sample

Question 27

Calibration curve

Answer 27

plotted absorbance and concentrations of a series of standard solution