How many atoms are there in 1.60 moles of selenium

There are 9.635 x 10^23 atoms in 1.6 moles of selenium

Explanation:

To solve this problem you have to use Avogadro´s constant (6.022 x 10^23).

In 1 mol of any element there are 6.022 x 10^23 atoms, so in 1.6 moles there will be...

1 mol Se 6.022 x 10^23 atoms

1.6 moles Se x = 9.635 x 10^23 atoms.

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles