amount of a substance

Question 1

what group 1 metals form

Answer 1

1+ ions

Question 2

what do group 2 metals form

Answer 2

2+ ions

Question 3

what does aluminium form

Answer 3

Al3+ ion

Question 4

what does silver form

Answer 4

Ag+

Question 5

what does zinc form

Answer 5

Zn2+

Question 6

what do ions end in

Answer 6

-ide

Question 7

ammonium nitrate

Answer 7

NH4+ & NO3-

NH4NO3

Question 8

lithium sulfide

Answer 8

Li+ & S2-
= Li2S

Question 9

aluminium oxide

Answer 9

Al3+ & O2-
= Al2O3

Question 10

magnesium hydroxide

Answer 10

Mg2+ & OH-
= Mg(OH)2

Question 11

calcium nitrate

Answer 11

Ca2+ NO3-
= Ca(NO3)2

Question 12

what does abundance tell us

Answer 12

how common each isotope is

Question 13

what do two main peaks of a mass spectrum graph show

Answer 13

shows elements main isotopes
(2 peaks = 2 main isotopes)

Question 14

what is m/z

Answer 14

relative mass of ion

Question 15

relative isotopic mass

Answer 15

mass of an atom of as isotope compared with 1/12th the mass of carbon-12

Question 16

relative isotopic mass

Answer 16

theres 1 relative isotopic mass for each isotope of an element
relative isotopic mass = always a whole number
has no units

Question 17

relative atomic mass

Answer 17

the average mass of an atom of an element compared to 1/12th the mass of carbon-12

Question 18

relative atomic mass formula (Ar)

Answer 18

(relative isotopic mass of isotope 1 x % abundance of isotope 1 ) + (relative isotopic mass of isotope 2 x % abundance of isotope 2)
/ 100

Question 19

molecular formula

Answer 19

tells us the elements in a molecule & number of atoms of each element
e.g Cl —Be —Cl = BeCl2

Question 20

define empirical formula

Answer 20

simple whole number ratio of the atoms of each element in a compound

Question 21

relative molecular mass (Mr)

Answer 21

weighted mean mass of a molecule compared with 1/12th the mass of an atom of carbon-12
(work out by adding relative atomic masses)

Question 22

relative formula mass

Answer 22

same as R.M.M

Question 23

avogadros constant (NA)

Answer 23

6.022 x 10^23 per mole
[number of particles in one mole of a substance]

Question 24

amount of substance (n)

Answer 24

number of moles we have of a substance
unit = moles

Question 25

molar mass (M)

Answer 25

mass of one mole of a substance
g mol-1

Question 26

amount of substance formula

Answer 26

amount of substance = mass (g) / molar mass (g/mol)

Question 27

number of particles formula

Answer 27

no. of particles = amount of substance (mol) X avogadro constant
[ first find amount of substance using mass / molar mass
then times by avogadro constant]

Question 28

volume of gas (dm3)

Answer 28

= amount of gas (mol) x 24.0

Question 29

ideal gas equation

Answer 29

pV=nRT

p = pressure (Pa)
V = volume (m3)
n = amount of substance (mol)
R = ideal gas constant
T = temp (K)

kilopascals —> pascals = x1000
dm3 —> m3 = /1000
cm3 —m3 = /1,000,000
degrees —> kelvin = +273