It is a scientific hypothesis. A scientific hypothesis must be testable, however there is a significantly more grounded necessity that a testable speculation must meet before it can truly be viewed as logical. This foundation comes essentially from crafted by the rationalist of science Karl Popper, and is called "falsifiability".
Because they both have to do with and chemistry science
Each mole of Ca(OH)₂ will produce 2 moles of OH- ions
Each mole of OH- ions will require one mole of H+ ions
Thus,
moles of OH- ions = moles of H+ ions = 2 x 0.3
moles of H+ ions required = 0.6
Each mole of HCl will produce one mole of H+ ions
Moles of HCl = moles of H+ ions
Moles of HCl = 0.6