How to convert from mole to number of molecules
Since 1 mole of any substance contains 6.02 x 1023 particles (Avogadro’s number), we can interpret the following equation: H2 + I2 –> 2HI in terms of moles and molecules.
1 mol of H2 reacts with 1 mol of I2 to form 2 mol of HI
Therefore, we can say that:
1 mole of H2 = 1
mole x 6.02 x 1023 molecules/1 mole = 6.02 x 1023 molecules of H2.
1 mole of I2 = 1
mole x 6.02 x 1023 molecules/1 mole = 6.02 x 1023 molecules of I2.
2 moles of HI = 2
mole x 6.02 x 1023 molecules/1 mole = 12.04 x 1023 molecules of HI.
So, you see, we just multiplied the coefficients in front each chemical by Avogadro’s number—- 6.02 x 1023 to get molecules for that particular chemical.
Below, we write the mole and number of molecules under each chemical.