1 mol of any thing(atoms ,balls ,bats, toffy ,etc) have Avogadro number(6.022x10^23) of that things
E.g 1 mol of sodium atoms have Avogadro number of Sodium atoms
SO 1 mol of Calcium atoms have Avogadro number of Calcium atoms
1 mol of Calcium have mass of 40 g(atomic weight )
5) what is the mass of 0.05 moles aluminum sulfate
aluminum sulfate=Al2(SO4)3
1 mol of Al2(SO4)3 have 2 mol of Al 6mol of S ans 12 mol of O
1 mol of Al2(SO4)3 weight 342 gmol-1(you can find this as i explain above in question 1 )
mass of 0.05 moles aluminum sulfate=0.05 molx342g mol-1=
17.1 g
6) the number of atoms in 2.4g of magnesium metal is
1 mol of Mg have Avogadro number(6.022x10^23) of Mg atoms
1 mol of Mg weight 24. gmol-1
2.4 g have (2.4g/24 gmol-1) =0.1 mol of Mg
0.1 mol contains (0.1mol x 6.022x10^23 mol-1)atoms=
6.022x10^22 atoms of Mg
7) what is the empirical formula of C8H603
empirical formula of a compound is lowest possible ratio between atoms of the compound
= C8H603
8) a certain coumpound has the following composition: C=40.0% and H=6.7 %. the emperical formula is
C=40.0%, H=6.7 % so O=100-(40+6.7)=53.3% by weight
if 100 g of compound taken then
there are 40 g of C
6.7 g of H
53.3 g of O
number of atoms of C in 100 g of compound =40/12
Like wise H=6.7/1
O=53.3/16
C:H:O=40/12:6.7:53.3/16
C:H:O=1:2:1=CH2O