Question

How many Br atoms are in 1.98 g of Br?

Answer 1

Answer:

1.5 x 10²²atoms

Explanation:

Given parameters:

Mass of Br = 1.98g

Unknown:

Number of atoms

Solution:

A mole of a substance is the amount of substance contained in the avogadro's number of particles.

To solve this problem, we must first find the number of moles present in the given mass of the Br atom:

       Number of moles = $\frac{mass}{molar mass}$ =  $\frac{1.98}{80}$  = 0.025mole.

Now we know that:

       1 mole = 6.02 x 10²³

      0.025 mole = 0.025 x 6.02 x 10²³ = 1.5 x 10²²atoms