1. Dissolve the weighed solid with about half the water you need in a beaker until a clear solution is obtained.
2. carefully transfer the solution into a selected volumetric flask.
3. wash out the beaker with a small portion of fresh water and add the washing in the flask.
4. repeat several times. then make up the solution to the mark on the flask by adding carefully from a wash bottle. when the solution level is reaching the mark add the water dropwise. this can be done using a medicine dropper. remember to read the solution level on the "bottom of the meniscuc"
5. put the cap on the flask and invert several times to make sure the solution is thoroughly mixed.