What do you mean by w/w solution ?
W/W generally means mass by mass, which is a common way of expressing concentration of a solution.
For details you may refer to the following link:
https://www.meritnation.com/ask-answer/question/is-concentration-in-terms-of-mass-by-mass-percentage-and-con/is-matter-around-us-pure/7902961
For details you may refer to the following link:
https://www.meritnation.com/ask-answer/question/is-concentration-in-terms-of-mass-by-mass-percentage-and-con/is-matter-around-us-pure/7902961