Question

What is the number of atoms in 0.25 moles of cobalt?

Answer 1

Number of mole s of H
2
​
= 0.25 moles
number of molecules = moles * Avogadro’s Number
number of molecules = 0.25×(6.022×10
23
)
number of molecules = 1.505×10
23

single molecule of hydrogen contains two H-atoms. So,
number of atoms = 2×(1.505×10
23
) = 3.01×10
23