Question

Calculate the number of molecules present in 4g NaOH.​

Answer 1

No. of moles of NaOH is given by

n=(Given mass)/(Molar mass)

= 4/40 = 0.1 mol

1 mol has 6.022 × 10^23 molecules.

Thus, 0.1 mol has 6.022 × 10^23 × 0.1 molecules i.e. 6.022 × 10^22 molecules.