2.1.6 Amount of substance and the mole

Question 1

what is the definition of Avogrado constant?

Answer 1

N*a, the number of atoms per mole of the carbon-12 isotope

Question 2

what is Avogrado constant number?

Answer 2

N*a = 6.02x10^23

Question 3

what the units of molar mass?

Answer 3

g mol^-1

Question 4

what is 6.02x10^23?

Answer 4

the number of atoms per mole of the carbon-12 isotope

Question 5

what is a mole?

Answer 5

the amount of any substance containing as many particles as there are in exactly 12g of the carbon-12 isotope

Question 6

what is molar mass?

Answer 6

M, is the mass per mole of a substance

Question 7

what is the definition of amount of substance?

Answer 7

the quantity that has moles as its units eg. similar to dozen

Question 8

formula for molar mass

Answer 8

moles = mass (g) / molar mass

Question 9

what is the symbol for moles?

Answer 9

mol

Question 10

what is relative isotopic mass?

Answer 10

mass compared with 1/12th mass of carbon-12

Question 11

what is relative atomic mass?

Answer 11

weighted mean mass compared with 1/12th mass of carbon-12

Question 12

what does weighted mean mass account for?

Answer 12

it accounts for the contribution of each isotope to the overall mass of the element

Question 13

when calculating Mr, what does a full stop mean?

Answer 13

water of crystallisation

Question 14

when calculating Mr (molar mass), what should you do if there is a full stop in-between two compounds/elements? eg CuSO4 .SH2O

Answer 14

just add them

Question 15

what does the suffix -ide mean?

Answer 15

that its the element only

Question 16

what does the suffix -ate mean?

Answer 16

that its bonded with oxygen (ALWAYS oxygen)

Question 17

what does the suffix -ite mean?

Answer 17

that is bonded with oxygen, however less than 8 oxygens

Question 18

how can you find the molar mass?

Answer 18

adding together all the relative atomic masses for each atom that makes the formula unit