3.95x10^25 atoms Cu2S to grams

Mass = 10440.9 g

Explanation:

Given data:

Number of atoms of Cu₂S = 3.95×10²⁵

Grams of Cu₂S = ?

Solution:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

For example,

18 g of water = 1 mole = 6.022 × 10²³ molecules of water

1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen

Now we calculate the number of moles from given number of atoms.

3.95×10²⁵ atoms/ 6.022 × 10²³ atoms × 1 mol

0.656×10² mol

65.6 mol

Now we will calculate the mass:

Mass = number of moles × molar mass

Mass = 65.6 mol × 159.16 g/mol

Mass = 10440.9 g

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