chemistry module 2 definitions

Question 1

Relative Abundance

Answer 1

the amount of one substance compared to another

Question 2

relative atomic mass

Answer 2

the weighted mean mass of an atom compared with 1/12th mass of
an atom of carbon-12.

Question 3

relative isotopic mass

Answer 3

the weighted mean mass of an isotope in comparison with 1/12th mass of an atom of carbon 12

Question 4

relative formula mass

Answer 4

the mass of the formula unit of a compound with a giant structure.
For example, NaCl has a relative formula mass of 58.44 g mol-1

Question 5

relative molecular mass

Answer 5

mr

Question 6

ionic compound

Answer 6

a compound which is made up of oppositely charged ions that are held
together by electrostatic forces.

Question 7

diff ions
-sulphate
-ammonium
-carbonate
-hydroxide
-nitrate
-silver
-zinc

Answer 7

-so4 2-
-nh4 +
-co3 2-
-oh -
-no3 2-
-ag +
-zn 2+

Question 8

state symbols

Answer 8

symbols within a chemical equation which indicate the state of each
compound under the reaction conditions. (g) gaseous, (l) liquid, (s) solid and (aq) aqueous

Question 9

amount of substance

Answer 9

the quantity that has moles as its units, used as a way of counting
atoms. The amount of substance can be calculated using mass (n = m/M), gas volumes (n =
pV/(RT)) or solution volume and concentration (n = CV)

Question 10

anhydrous

Answer 10

a crystalline compound containing no water.

Question 11

atom economy

Answer 11

a measure of the amount of starting materials that end up as useful
products. A high atom economy means a process is more sustainable as there is less waste
produced

Question 12

avogadro’s constant

Answer 12

the number of particles per mole of substance (6.02 x 1023 mol-1).

Question 13

composition by mass

Answer 13

the relative mass of each element in a compound

Question 14

hydrated

Answer 14

a crystalline compound that contains water

Question 15

ideal gas

Answer 15

a gas which has molecules that occupy negligible space with no interactions
between them. The ideal gas equation is: pV = nRT

Question 16

stoichiometry

Answer 16

the relative quantities of substances in a reaction

Question 17

water of crystallisation

Answer 17

water molecules that form part of the crystalline structure of a
compound.

Question 18

acid

Answer 18

compounds that release H+
ions in aqueous solution. Common acids include: HCl,
H2SO4
, HNO3
and CH3COOH

Question 19

alkali

Answer 19

water soluble bases. Alkalis release OH-
ions into aqueous solution. Common alkalis
include: NaOH, KOH and NH3

Question 20

bases

Answer 20

accept H+ ions but do not have to be water soluble, the ones that are are called alkalis

Question 21

neutralisation

Answer 21

a reaction between H+
and OH-
, forming water. This may be a reaction
between an acid and a base to form a salt (types of bases include carbonates, metal oxides
and alkalis)

Question 22

strong acid

Answer 22

an acid that completely dissolves in solution

Question 23

titration

Answer 23

a technique used to determine the amount of one solution of a known
concentration required to completely react with a known volume of another solution of
unknown concentration.

Question 24

weak acid

Answer 24

an acid that only partially dissociates in solution

Question 25

how much more do lone pairs repel by

Answer 25

2.5 degrees

Question 26

2BP 0LP

Answer 26

linear, 180 degrees

Question 27

3BP

Answer 27

trigonal planar, 120 degrees

Question 28

2BP 1LP

Answer 28

bent,less than 109.5

Question 29

4BP

Answer 29

tetrahedral, 109.5

Question 30

3BP, 1LP

Answer 30

trigonal pyramid, around 107

Question 31

2BP, 2LP

Answer 31

non-linear (2), 104.5

Question 32

5BP

Answer 32

trigonal bipyramidal, 120 or 90 degrees

Question 33

4BP, 1LP

Answer 33

seesaw, 89 or 119 degrees

Question 34

3BP, 2LP

Answer 34

t shaped, 120 or 89 degrees

Question 35

6BP

Answer 35

octahedral, 90 degrees

Question 36

5BP, 1LP

Answer 36

square pyramidal, 89

Question 37

4BP, 2LP

Answer 37

square planar, 90