Question

molar mass (grams/mol) = average atomic mass (u/atom)

Answer 1

need understanding on how this all works out, history of how we arrived at this plz kindly help actually i dont see how they figured out Avogadro's number thats where i got stuck plz help

Answer 2

since atoms are very small there masses are very small hence to measure the small mass unit of kilogram was inconvenient that's why we need some smaller unit and that is being choosen as atomic mass unit or in term of moles it is molecular mass.

Answer 3

yea makes sense so far

Answer 4

is this right :

by definition, amu = 1/12 the mass of C atom

then,

12 grams of C will have 1 mole C atoms, and
one C atom will have a mass of 12 amu

?

Answer 5

well it is true

Answer 6

1 carbon atom= 12 amu= Avogadro's number

Answer 7

ok this may help you to understand it

1 amu is defined as 1/12 of the mass of one C atom.
as 12g of C contains 6.023x 10^23 atoms of C

so mass of C is 12/6.023x10^23

by definition
1 amu = 1/12 ( 12/ 6.023x10^23 ) g
= 1/6.023x10^23 g
= 1.66x10^-24 g

Answer 8

so 1amu= 1.66x10^-24g
= 1.66x10^-27 kg

Answer 9

wow thats almost close to mass of proton

Answer 10

yep !

Answer 11

if i get it correctly, they first measured the mass of C in grams

Answer 12

i mean they measured the mass of C atom in grams

Answer 13

yes !

Answer 14

it would be, 12 (1.66x10^-27 kg )

Answer 15

then, once they have mass of C atom

Answer 16

they wanted to represent all other elements masses in terms of C atom, so they defined amu = 1/12 of C mass

Answer 17

right ?

Answer 18

Molar mass is the weight of one mole of any chemical compounds. Atomic mass is the weight of just 1 atom of a compound

Answer 19

how they figured out how much a mole represent, coz the mass of mole atoms in grams is same as mass of 1 atom in amu

*the number is same, not the quantity

Answer 20

somehow i dont see whats actually happening.. this may turn out simple though