The atoms of a substance can be determined by dividing the given mass of the substance by the molar mass. This results to moles of the substance. Then we multiply by the Avogadro's number. In this case, we divide 1 g by 58. 69 g/ mol and multiply by 6.022 x10^23 atoms / mole. The answer is 1.03 x10^22 atoms
In this case, for a concentration of 0.42 M of benzoic acid whose Ka is 6.3x10⁻⁵ in 0.33 M sodium benzoate, we use the Henderson-Hasselbach equation to compute the required pH:
Whereas the concentration of the base is 0.33 M and the concentration of the acid is 0.42 M, thereby, we obtain: