Question

How many grams of calcium are made up by 2.68 x 1023 atoms?

Answer 1

Answer:

Mass = 17.8 g

Explanation:

Given data:

Number of atoms of Ca = 2.68 × 10²³

Mass in gram = ?

Solution:

Avogadro number:

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 atoms

2.68 × 10²³ atoms × 1 mole  /6.022 × 10²³ atoms

0.445 mol

Mass in gram;

Mass = number of moles ×  molar mass

Mass = 0.445 mol  ×  40 g/mol

Mass = 17.8 g