They both have a different number of moles
Further explanation
Given
40 g HCl
40 g NaHCO3
Required
moles
Solution
The mole is the number of particles contained in a substance
1 mol = 6.02.10²³
Moles can also be determined from the amount of substance mass and its molar mass
n = mass : molar mass
So the moles of a compound are affected by its molar mass (inversely proportional)
The larger the molar mass (of the same mass), the smaller the moles
molar mass HCl = 58.5 g/mol
molar mass NaHCO3 = 84 g/mol
mol HCl :
= 40 : 58.5
= 0.684
mol NaHCO# :
= 40 : 84
= 0.476