Question

Calculate the number of:
(a) Particles in 0.1 moles of any substance,
(b) Hydrogen atoms in 0.1 mole of $H_{2}S{O}_4$
(c) Molecules in one kg of calcium chloride.

Answer 1

a) No. of particles in 1 mole = $6.023\times {10}^{23}$

So, particles in 0.1 mole $=6.023\times {10}^{23}\times 0.1=66.023\times {10}^{22}$

b) 1 mole of $H_{2}S{O}_4$ contains $=2\times 6.023\times {10}^{23}$ atoms of hydrogen.

So, 0.1 mole of $H_{2}S{O}_4$​​​​​​​ contains $=2\times 6.023\times {10}^{23}\times 0.1=1.2\times {10}^{23}$ atoms of hydrogen

c) 111g $CaC{l}_2$ contains $=6.023\times {10}^{23}$ molecules
So, 1000 g contains $=5.42\times {10}^{24}$ molecules