chem-moles

number of moles = mass/molar mass

So, 1=60/molar mass
so the molar mass is 60g

2006-10-23 00:25:18 補充：
should be:no of moles of XO2=no of moles of atoms in XO31 = 4 * mass of XO3 / molar mass of XO3 (there are 4 atoms in the XO3 molecule)1= 4 * 60/molar massmolar mass = 240g

x moles of XO3 gives 60g and 4x mole of atoms
1 mole of XO2 gives 3 moles and 4x mole of atoms
Therefore, x=0.75

molar mass
= mass per mole of substance
= mass/ no. of moles
= 60/0.75
=80 (g)

1 mole既野擁有相同既數量, 即 6.02 * 10^23

不過後者係講atoms既數目, 而1 mole既 XO3 就有 4 moles既atoms

所以, 1 mole XO2 = 1/4 mole XO3
所以, XO3 既molar mass (1 mole既mass) 係 60 * 4 g = 240 g

mole of X02 contains the same number of atoms