Find the number of grams in 3.45 x 10^21 molecules NiO

Mass = 0.43 g

Explanation:

Given data:

Mass in gram = ?

Number of molecules of NiO = 3.45×10²¹

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.

1 mole = 6.022 × 10²³ molecules

3.45×10²¹ molecules × 1 mol / 6.022 × 10²³ molecules

0.57×10⁻² mol

0.0057 mol

Mass in gram:

Mass = number of moles × molar mass

Mass = 0.0057 mol × 74.69 g/mol

Mass = 0.43 g

it's c. elements are placed in rows based on how may valencies electrons have.