Question

How many molecules are in a 189 g sample of carbon tetrabromide, CBr4 ?

Answer 1

Answer:

3.4 × 10²³ molecules of CBr₄

Explanation:

Given data:

Mass of CBr₄ = 189 g

Number of molecules = ?

Solution:

First of all we will calculate the number of moles.

Number of moles = mass / molar mass

Number of moles = 189 g/ 331.63 g/mol

Number of moles = 0.6 mol

Now 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

Foe 0.6 moles of CBr₄:

0.6 mol × 6.022 × 10²³ molecules of CBr₄ / 1 mol

3.4 × 10²³ molecules of CBr₄