Both sucrose and lactose are disaccharides. Sucrose on hydrolysis gives one molecule each of glucose and fructose but lactose on hydrolysis gives one molecule each of glucose and galactose.
`underset("Sucrose")(C_(12) H_(22) O_(11)) + H_(2)O overset(H_(3) O^(+)) rarr underset(D - (+) - "Glucose")(C_(6) H_(12) O_(6)) + underset(D - (-) -"Fructose")(C_(6) H_(12) O_(6))`
`underset("Lactose")(C_(12) H_(22) O_(11)) + H_(2) O overset(H_(3)O^(+))rarr underset(D - (+) - "Glucose")(C_(6) H_(12)O_(6)) + underset(D - (+) - "Galactose")(C_(6) H_(12) O_(6))`