The question says only to convert the Zn(OH)₂ into moles. But the given answer has many errors such as formula, mass and moles.
The corrected answer is as follows.
Moles (mol) = mass (g) / molar mass (g/mol)
Mass of Zn(OH)₂ = 0.45 g
Molar mass of Zn(OH)₂ = 99.424 g/mol
Hence, moles of Zn(OH)₂ = 0.45 g / 99.424 g/mol
= 4.526 x 10⁻³ mol