calcukation

Question 1

relative atomic mass definition

Answer 1

weighted average mass of an atom relative to 1/12th the mass of a C-12 atom

Question 2

relative atomic mass (Ar)

Answer 2

(mass no. 1 x abundance1) + (mass no. 2 x abundance 2) /100

Question 3

relative molecular mass (Mr)

Answer 3

when a substance is simple molecular
add up relative atomic mass of all atoms in a molecule
H2O - 1+1+16 = 18

Question 4

relative formula mass (RFM)

Answer 4

when substance is ionically bonded

add up relative atomic mass of all atoms

Question 5

relative formula mass of substance containing water of crystallisation

Answer 5

same as RFM
x.5H2O
x + 5x 18

Question 6

mole

Answer 6

6x10^23

Question 7

mole equation

Answer 7

mass = Mr x mole

Question 8

% yield

Answer 8

actual / theoretical (x100)

Question 9

why yield is less than 100%

Answer 9

• substances lost in transfer
• side reactions take place
• reversible reactions

Question 10

molecular formula definition

Answer 10

how many of each atom in a molecule (simple molecular)

Question 11

empirical formula definition

Answer 11

lowest ratio of atoms in a compound

Question 12

empirical formula

Answer 12

mass/Ar

answer/smallesr