Q 2. Which has more number of atoms, 100 grams of sodium or 100 grams of iron (given, atomic mass of Na = 23 u, Fe = 56 u)?
The number of moles of 100 g Na atoms :
The number of moles in 100 g of Fe atoms :
As we know, the one-mole atoms contain atoms.
So, more the number of moles, more the number of atoms. and hence 100 g of Na atom has a greater number of atoms than 100 g Fe.
Given
Atomic mass of Na =23u
Atomic mass of Fe =56u
Then gram atomic mass of Na =23gram Now 23 g of na contains = 6.022 ×1023 g no of atoms ,Thus 100 g of na contains 2.6182×1023 no then gram of atomic mass of Fe =56g , now 56 gram of Fe contains 6.022 × 1023 g no of atoms thus hundred g of Fe contains 6.022× 1023 /56 × 100 numbers of atoms
100 g of Fe contains = 1.0753× 1024 number of atoms