Question

how many gram atom and no of atoms are there in (a)=60g of C (B)= 224.4g of cu (C)= 72.52g of pb .. plzzz ans me plzz

Answer 1

(a) atomic mass of carbon is 12
Hens number of Gram atoms present in carbon are equals to
= given gram mass of C / atomic mass of c
= 60 / 12 = 5 gm atoms

(1) 1 gram atom is equal to mole
hence , 5 gram of atom = to 5 moles

(2)if we have to calculate number of atoms present in carbon then simply multiply Avogadro number (NA) to its given number of moles or gram atoms of carbon .

Hens number of atoms of carbon are equals to
➡ =5 * NA =5✖ 6.022*10^23 = 30 * 10^23
: number of Gram atoms are = 5 ND number of atoms are = 30*10^23

(b) atomic mass of copper is 63.54
Hens number of Gram atoms of cu are equals to ➡ = 224.4 / 63.54 = 3.5 gram atoms

number of atoms of cu are ➡ = 3.5 *6.022* 10^23 = 21.3 * 10^23

⏩⏩hence number of Gram atoms of cu are = 3.5 ND number of atoms of cu are =
21.3 *10^23

(c) atomic mass of pb is 207 gm

Hens number of Gram atoms in pb are equals to ➡= 72 .52 / 207 = 0.35 gm atoms help number of atoms in pb are equals to
➡ = 0.35 ✖ 6.022 *10 ^23 = 2.1 *10^ 23 atoms
⏩⏩ Hens number of Gram atoms in pb
= 0.35 ND no. of atoms in pb are = 2.1 * 10^23 .