c% = md x 100 / ms
=> md = ms x c% / 100 = 200 x 5 / 100 = 10 g Ca(OH)2
md...................... 10 g
2CH3COOH + Ca(OH)2 => (CH3COO)2Ca + H2O
2x60 g/mol..........74 g/mol
md = 2x60x10/74 = 16,22 g CH3COOH
c% = 10%
=. ms = mdx100/c% = 162,2 g sol. CH3COOH