How many atoms are in
grams of lead?
Answers
Answered by
12
Molar mass of Pb is 207.2g
1 mole of Lead (207.2g) contains 6.022x10²³ atoms
1x10⁻⁹ g of lead contains --------?
=1x10⁻⁹x6.022x10⁻²³/207.2
=10¹⁴x0.029
=2.9x10¹²
∴ 2.9 x 10¹² atoms are present in 1x 10⁻⁹g lead
Answered by
2
given weight of lead , w = 10^-9 gram
atomic mass of lead {e.g. Pb } , M = 207.2 g/mol
number of mole of lead = weight of lead/atomic mass of lead
= 10^-9/207.2
number of atoms = number of mole of lead × Avogadro's number
= 10^-9/207.2 × 6.023 × 10²³
= 0.029068 × 10¹⁴
= 2.9 × 10¹²
hence, number of atoms in 10^-9 gram of lead = 2.9 × 10¹²
atomic mass of lead {e.g. Pb } , M = 207.2 g/mol
number of mole of lead = weight of lead/atomic mass of lead
= 10^-9/207.2
number of atoms = number of mole of lead × Avogadro's number
= 10^-9/207.2 × 6.023 × 10²³
= 0.029068 × 10¹⁴
= 2.9 × 10¹²
hence, number of atoms in 10^-9 gram of lead = 2.9 × 10¹²
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