The molecular weight and equivalent weight of which one of the following is the same?

The equivalent weight of a substance is defined as its molecular weight divided by its n-factor (valency factor) [t1][t5]. For acids, the n-factor is the number of ionizable hydrogen ions (basicity), while for bases, it is the number of ionizable hydroxide ions (acidity) [t2][t4]. NaOH (Sodium Hydroxide) is a monoprotic base that dissociates to release one OH⁻ ion; thus, its n-factor is 1 [t5]. Consequently, its equivalent weight (40/1) is equal to its molecular weight (40) [t5]. In contrast, H2SO4 (Sulfuric acid) and H2C2O4 (Oxalic acid) are diprotic acids with an n-factor of 2, making their equivalent weights half of their molecular weights [t2][t7]. KMnO4 (Potassium Permanganate) acts as an oxidizing agent where its n-factor varies (usually 5 in acidic media), resulting in an equivalent weight different from its molecular weight [t6].

Sources

1. [1] https://pubs.usgs.gov/wri/1989/4029/report.pdf
2. [2] https://en.wikipedia.org/wiki/Equivalent_weight